Unclogging America`s Arteries - American Highway Users Alliance

Transcription

Unclogging America’s Arteries
Effective Relief for Highway Bottlenecks
Saving Lives
Conserving Fuel
Preventing Injuries
Improving the Economy
Cutting Commute Times
Accelerating Cleaner Air
Reducing Greenhouse Gases
1999 - 2004
ACKNOWLEDGEMENTS
This report was made possible thanks to the generosity of a number of
contributing partners. Sponsors include:
Platinum Level
www.autoalliance.org
Gold Level
www.cement.org
www.nssga.org
Silver Level
www.agc.org
www.aednet.org
In addition, the Highway Users recognizes the National Ready
Mixed Concrete Association for its support.
Finally, the Highway Users would like to thank the American
Association of State Highway and Transportation Officials
(AASHTO) for the group’s assistance and cooperation in developing
this study.
UNCLOGGING AMERICA’S ARTERIES
1999-2004
American Highway Users Alliance
One Thomas Circle, NW
Tenth Floor
Washington, DC 20005
Phone: 202-857-1200
Fax: 202-857-1220
www.highways.org
About the American Highway Users Alliance
About Cambridge Systematics
The American Highway Users Alliance is a nonprofit advocacy
organization serving as the united voice of the transportation
community promoting safe, congestion-free highways and
enhanced freedom of mobility. Known as the Highway Users, the
group has worked for sound transportation policy in the United
States since 1932.
Cambridge Systematics is an internationally recognized,
employee-owned consulting firm that has been providing
planning, policy, and management solutions for more than 25
years. Cambridge Systematics applies state-of-the-art analytical
techniques to develop innovative, practical solutions for clients in
many areas, including transportation planning and management,
travel demand forecasting, CVO, ITS, information technology,
asset management, and market research.
The Highway Users represents motorists, truckers, bus companies
and a broad cross-section of businesses that depend on safe
and efficient highways to transport their families, customers,
employees and products. Our members pay the taxes that finance
the federal highway program and advocate public policies that
dedicate those taxes to improved highway safety and mobility.
The Highway Users regularly publishes studies on transportation
trends and developments, as well as reports on other pertinent
issues that affect highway safety and mobility. For more
information, visit our web site at www.highways.org.
© Copyright February 2004
by the American Highway Users Alliance.
Prepared for the American Highway Users Alliance
by Cambridge Systematics, Inc.
All rights reserved.
The firm’s headquarters is located in Cambridge, Massachusetts,
with other offices in Oakland, California; Washington, DC;
Chicago, Illinois; Seattle, Washington; Princeton, New Jersey;
Denver, Colorado; and Knoxville, Tennessee.
Cambridge
Systematics serves a broad mix of public organizations and
private corporate clients. These organizations include a variety
of local, state, national, and international agencies, as well as
transportation, logistics, telecommunications, and manufacturing
companies; electric utilities; banks; and other private corporations
and business organizations.
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Nonmember Price: $75
Table of Contents
I. Executive Summary
1
II. Introduction: A Primer on Highway Bottlenecks
and the Benefits of Congestion Relief
4
III. Effective Relief for America’s Worst Bottlenecks
11
Ranking the Bottlenecks
11
What Has Changed in the Past Five Years?
13
America’s Worst Bottlenecks and the Benefits of Fixing em
18
Success Story: US-59 (Southwest Freeway)/I-610 Loop in Houston
Success Story: e “Big I” in Albuquerque
Success Story: I-25/I-225 Interchange in Denver
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
14)
15)
16)
17)
18)
19)
20)
21)
22)
23)
24)
Los Angeles, CA: US-101 (Ventura Fwy) at I-405 Interchange
Houston, TX: I-610 at I-10 Interchange (West)
Chicago, IL: I-90/94 at I-290 Interchange (“Circle Interchange”)
Phoenix, AZ: I-10 at SR-51/SR-202 Interchange (“Mini-Stack”)
Los Angeles, CA: I-405 (San Diego Fwy) at I-10 Interchange
Atlanta, GA: I-75 at I-85 Interchange
Washington, DC (MD): I-495 at I-270 Interchange
Los Angeles, CA: I-10 (Santa Monica Fwy) at I-5 Interchange
Los Angeles, CA: I-405 (San Diego Fwy) at I-605 Interchange
Atlanta, GA: I-285 at I-85 Interchange (“Spaghetti Junction”)
Chicago, IL: I-94 (Dan Ryan Expwy) at I-90 Skyway Split (Southside)
Phoenix, AZ: I-17 (Black Canyon Fwy) at I-10 Interchange (the “Stack”) to Cactus Rd.
Los Angeles, CA: I-5 (Santa Ana Fwy) at SR-22/SR-57 Interchange (“Orange Crush”)
Providence, RI: I-95 at I-195 Interchange
Washington, DC (MD): I-495 at I-95 Interchange
Tampa, FL: I-275 at I-4 Interchange (“Malfunction Junction”)
Atlanta, GA: I-285 at I-75 Interchange
Seattle, WA: I-5 at I-90 Interchange
Chicago, IL: I-290 (Eisenhower Expwy) Between Exits 17b and 23a
Houston, TX: I-45 (Gulf Freeway) at US-59 Interchange
San Jose, CA: US-101 at I-880 Interchange
Las Vegas, NV: US-95 at I-15 Interchange (“Spaghetti Bowl”)
San Diego, CA: I-805 atI-15 Interchange
Cincinnati, OH: I-75, from Ohio River Bridge to I-71 Interchange
Bottlenecks Nationwide: Benefits Analysis
15
16
17
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50
52
54
56
58
60
62
64
66
68
IV. Summary and Conclusions
70
Appendix A: Methodology
72
Appendix B: Major Bottlenecks State-by-State
78
Appendix C: Major Bottlenecks Ranked 1 to 233
87
EXECUTIVE SUMMARY
T
he American Highway Users Alliance in 1999 released a first-of-its-kind study examining a significant
cause of traffic congestion – the country’s worst highway bottlenecks. In the five years that have
passed, two trends have become unmistakably clear.
Congestion Has Grown Across the U.S. . . .
In 1999, we identified 167 major highway bottlenecks located in 30 states plus the District of Columbia.
Using the same methodology and delay criteria, the number of severe traffic chokepoints in the U.S. where
drivers experience at least 700,000 hours of delay annually has now increased to a total of 233 bottlenecks
in 33 states plus the District, a 40 percent increase.
. . . . But Improvements Are Possible
Seven of the top 18 bottlenecks we identified five years ago – including hot spots in Houston, Albuquerque,
Denver, Boston, Chicago, Los Angeles and Washington, DC – no longer appear on our ranking of the
country’s worst chokepoints because major reconstruction projects are either completed or underway to
improve traffic flow at these sites. In Albuquerque alone, motorists have regained more than 15 million
hours each year that would have otherwise been wasted sitting in traffic at the I-40/I-25 interchange, also
know at the “Big I.”
Similar improvements are possible nationwide. Over the 20-year life of the projects, modest improvements
to improve traffic flow at the 233 severe bottlenecks we identify in this report would prevent more than
449,500 crashes (including some 1,750 fatalities and 220,500 injuries). Carbon dioxide emissions would
drop by an impressive 77 percent at these bottlenecks and more than 40 billion gallons of fuel would be
conserved. Emissions of smog-causing volatile organic compounds would drop by nearly 50 percent,
while carbon monoxide would be reduced by 54 percent at those sites. Rush hour delays would decline by
74 percent, saving commuters who must negotiate these bottlenecks an average of more than 30 minutes
each day.
I. EXECUTIVE SUMMARY
The Benefits of Unclogging America’s Arteries
T
his updated study attempts to quantify the benefits Americans can realize if major bottlenecks are
eliminated, and conversely, the price to be paid if congestion is allowed to increase. The benefits of
congestion relief include:
n
Saving Lives. Traffic congestion causes highway crashes that can kill drivers, their passengers and
others. As highway crowding increases and motorists jockey for position at exits and entryways,
the potential for crashes increases. Improving bottlenecks saves lives and averts injuries.
n
Improving the Environment. Bottlenecks retard the nation’s otherwise impressive progress in
improving air quality. Vehicles caught in stop-and-go traffic emit far more pollutants – particularly
carbon monoxide and volatile organic compounds – than they do when operating without frequent
braking and acceleration. Improving bottlenecks reduces tailpipe pollutants.
n
Reducing Greenhouse Gas Emissions. Vehicles emit carbon dioxide, a greenhouse gas, as fuel is
consumed. Because congestion relief has a direct effect on fuel consumption, improvement projects
will significantly reduce greenhouse gas emissions.
n
Conserving Fuel. The longer vehicles are delayed in traffic, the more fuel they consume. Nationwide,
5.7 billion gallons of fuel are wasted annually because of congestion.
n
Saving Time. Traffic congestion is a major source of frustration for American motorists, adding
stress to our already busy lives. Reducing road delays eases that frustration and means more time
for families, errands, work and play.
American Highway Users Alliance • Effective Relief for Highway Bottlenecks • www.highways.org
1
n
Enhancing Productivity. Bottlenecks also delay product deliveries, inhibiting productivity
and raising costs. Businesses suffer direct economic consequences because of congestion. In
the world of “just-in-time” deliveries, time really is money. Congested roadways can also
discourage businesses from locating facilities and bringing jobs to urban areas. Improving
bottlenecks boosts productivity and economic health.
F
or more than a decade, conventional wisdom has held that gridlock is an unavoidable part of
modern life. Some elected officials, others in the media, and even many motorists seem resigned
to the “fact” that congestion can only get worse – certainly never better.
While past experience shows that no single strategy can adequately address the problems of
metropolitan congestion, the good news is that there are effective solutions that can reduce traffic
congestion. This study shows that metropolitan areas can realize significant benefits by focusing on
improvements to major traffic bottlenecks as a first step in an overall congestion relief plan.
A balanced, comprehensive approach to traffic congestion that uses all the tools at our disposal can
reduce the stifling gridlock found on many of our highways. This approach can include improving
the safety and convenience of public transportation. We also need to use the roads we already have
in the most efficient way possible. Investing in smart road technologies – such as synchronized traffic
lights, computerized systems to route traffic around congested areas, and options like reversible
commuter lanes and movable barriers that add capacity during peak hours of travel – will help.
But in many instances, as highlighted by the bottlenecks profiled in this report, our overstressed
road system needs additional capacity at key points. Providing that capacity by removing strategic
bottlenecks as part of a comprehensive congestion relief program will reduce the amount of time
commuters have to spend on the road, save thousands of lives, prevent hundreds of thousands of
injuries and help safeguard the environment.
Bottlenecks Plague Commuters in 33 States Nationwide
Urban Areas with a
Top 24 Bottleneck
Urban Area with
Major Bottlenecks
2
American Highway Users Alliance • Unclogging America’s Arteries 1999-2004 • www.highways.org
America’s Worst Highway Bottlenecks
Annual
Hours of
Delay
Rank
City
Freeway
Location
Vehicles
per Day
1
Los Angeles
US-101
US-101 (Ventura Fwy) at I-405 Interchange
318,000
27,144
2
Houston
I-610
I-610 at I-10 Interchange (West)
295,000
25,181
3
Chicago
I-90
I-90/94 at I-290 Interchange (“Circle Interchange”)
293,671
25,068
4
Phoenix
I-10
I-10 at SR-51/SR-202 Interchange (“Mini-Stack”)
280,800
22,805
5
Los Angeles
I-405
I-405 (San Diego Fwy) at I-10 Interchange
296,000
22,792
6
Atlanta
I-75
I-75 at I-85 Interchange
259,128
21,045
7
Washington (DCMD-VA)
I-495
243,425
19,429
8
Los Angeles
I-10
I-10 (Santa Monica Fwy) at I-5 Interchange
318,500
18,606
9
Los Angeles
I-405
318,000
18,606
10
Atlanta
I-285
I-285 at I-85 Interchange (“Spaghetti Junction”)
266,000
17,072
11
Chicago
I-94
I-94 (Dan Ryan Expwy) at I-90 Skyway Split (Southside)
260,403
16,713
12
Phoenix
I-17
I-17 (Black Canyon Fwy) at I-10 Interchange (the
“Stack”) to Cactus Rd.
208,000
16,310
13
Los Angeles
I-5
I-5 (Santa Ana Fwy) at SR-22/SR-57 Interchange
(“Orange Crush”)
308,000
16,304
14
Providence
I-95
256,000
15,340
15
I-495
185,125
15,035
16
Tampa
I-275
I-275 at I-4 Interchange (“Malfunction Junction”)
201,500
14,371
17
Atlanta
I-285
239,193
14,333
18
Seattle
I-5
301,112
14,306
19
Chicago
I-290
I-290 (Eisenhower Expwy) Between Exits 17b and 23a
200,441
14,009
20
Houston
I-45
I-45 (Gulf Freeway) at US-59 Interchange
250,299
13,944
21
San Jose
US-101
US-101 at I-880 Interchange
244,000
12,249
22
Las Vegas
US-95
US-95 at I-15 Interchange (“Spaghetti Bowl”)
190,600
11,152
23
San Diego
I-805
238,000
10,992
24
Cincinnati
I-75
I-75, from Ohio River Bridge to I-71 Interchange
136,013
10,088
3
INTRODUCTION
A Primer on Highway Bottlenecks and the Benefits of Congestion Relief
What This Study Is About
H
ighway traffic congestion is a major source of frustration for American travelers, causing an
estimated 3.5 billion hours of delays per year in 75 of the largest metropolitan areas.1 Put another
way, in the 10 largest metropolitan areas, trips during rush hours take an average of 52 percent longer
than if they occurred when no congestion was present. In the next 30 largest cities, rush hour trips take
32 percent longer because of congestion.2
Besides adding to the frustration and stress levels of American drivers, traffic congestion also has strong
economic, environmental and safety consequences. When vehicles are delayed in traffic, they emit far
more pollutants and consume far more fuel than if traffic congestion did not exist: an estimated 5.7 billion
gallons are wasted because of congestion in 75 of the largest cities.3 In addition, as highway crowding
increases, so does the potential for crashes. Businesses also suffer direct economic consequences because
of congestion. In the world of “just-in-time” delivery services, time really is money. Finally, businesses
and individuals often decide where to locate based on congestion patterns in a metropolitan area.
When dollar figures are assigned to the value of travel time and excess fuel consumed, the cost of
congestion is staggering: $70 billion in 2001.4 If environmental, safety and relocation costs had been
included, this figure would be much higher.
T
his study is an update to our 1999 study, Unclogging America’s Arteries: Prescriptions for Healthier
Highways. That study was the first national-level analysis examining a major cause of traffic
congestion: the highway bottleneck. By updating that initial work we are able to develop comparisons
and analyze trends in congestion patterns five years later.
Bottlenecks are something that most motorists can easily identify. In nearly every American city, there are
one or more highway locations that have notorious reputations among travelers – heavy traffic congestion
occurs in these areas every weekday, and sometimes on weekends, for several hours during the morning
and afternoon rush periods. As described in more detail later in this Introduction, a bottleneck is a
specific, physical location on the highway that routinely experiences traffic backups. We have focused
on bottlenecks because they are easily recognized and because their removal can lead to immediate and
positive improvements in traffic flow. Also, average national statistics, such as those reported above, can
mask the most serious problems experienced by many travelers; identifying bottleneck locations draws
attention to these extreme conditions. Specifically, we have set three objectives for this study:
II. INTRODUCTION
1. Identify the worst traffic bottlenecks in the United States, recognizing that some cities may have
more than one. We have focused in detail on those bottlenecks that create the longest delays for
travelers, limiting our consideration to interstate highways and other freeways. We also make
comparisons with the conditions found in our 1999 study.
4
2. Estimate the benefits to travelers and the environment by removing the bottlenecks, based on the
actual improvement plans if they exist. The benefit estimation is driven by a set of assumptions
and analysis methods, as detailed in Appendix A. To show that those benefits are not simply
theoretical, we also highlight several “success stories” – bottlenecks from our 1999 study that have
since been improved.
3. Estimate the benefits that would be derived from removing bottlenecks nationwide. There are many
more bottlenecks in the country than the top 24 on which we have focused. These bottlenecks
occur not only in the major metropolitan areas, but also in smaller ones. We examine the effects of
improving these bottlenecks.
1 Schrank, David and Lomax, Tim, The 2003 Annual Urban Mobility Report, Texas Transportation Institute, Texas A&M University,
September 2003.
2 Schrank and Lomax, 2003.
Highway Travel in Metropolitan Areas: Is It Getting Better or Worse?
We begin with an examination of recent trends in congestion. The best single source for monitoring
congestion trends is produced annually by the Texas Transportation Institute (TTI). In their 2003 report,
TTI’s researchers found that congestion levels have grown continuously between 1990 and 2001:
n
Peak period5 trips take on average 10 percent longer.
n
The annual hours of delay experienced by individual commuters has grown from 18 hours per
year to 26 hours.
n
The percentage of congested freeway mileage has grown from 43 percent to 55 percent.
The researchers also observe more long-term trends:
n
“Congestion extends to more time of the day, more roads, affects more of the travel and creates
more extra travel time than in the past. And congestion levels have risen in all size categories,
indicating that even the smaller areas are not able to keep pace with rising demand.”
n
“Congestion has spread significantly over the 20 years of the study. A few notable changes from
1982 to 2001 include:
• 27 urban areas have a Travel Time Index6 above 1.30 compared with one such area in 1982.
• 67 percent of the peak period travel is congested compared to 33 percent in 1982.
• 59 percent of the major road system is congested compared to 34 percent in 1982.
• The number of hours of the day when congestion might be encountered has grown from about
4.5 hours to about 7 hours.”
TTI’s researchers also note that despite the economic slowdown in 2001, congestion levels increased
slightly between 2000 and 2001. Given these statistics, an economy that is on the verge of expansion and
continued population growth, we can expect further increases in traffic congestion for the foreseeable
future.
Creeping Congestion: Congestion Outside of Metropolitan Areas
Congestion is not just a problem for city dwellers. Analysis of data reported to the Federal Highway
Administration reveals a dramatic trend: Since 1992, traffic has grown substantially on rural highways
and at a faster pace than on metropolitan highways. The table below shows that between 1992 and
2002, traffic on rural interstates increased 36 percent compared with an increase of 26 percent on urban
interstates. Further analysis shows that traffic volumes per available lane increased by 35 percent on rural
interstates compared with 23 percent on urban interstates. Further, trucks now comprise eight percent
more of the rural interstate traffic stream than they did in 1992. (Over 26 percent of rural interstate traffic
is now comprised of trucks.) By 2010, 16 percent of rural interstate mileage will be operating at what
is generally considered to be unacceptable crowding levels for rural conditions,7 while 11 percent will
experience actual congestion.8
Growth in Key Traffic Statistics, 1992–2002
TRAFFIC STATISTIC
RURAL INTERSTATE GROWTH
URBAN INTERSTATE GROWTH
Total Daily Volume
+36%
+26%
Daily Volume per Traffic Lane
+35%
+23%
Trucks in Traffic Stream
+8%
+4%
Source: Analysis of Highway Performance Monitoring System data
5 In most metropolitan areas, the idea of “rush hour” is obsolete – congestion happens for multiple hours on both morning and evening weekdays.
6 Travel Time Index is the ratio of actual travel time for a trip compared to the “ideal” travel time for a trip. Thus, a Travel Time Index of 1.30
indicates that the trip takes 30 percent longer than it would under “ideal” or uncongested conditions.
7 Levels of Service D through F, as defined in the Highway Capacity Manual, Transportation Research Board.
8 Levels of Service E and F.
5
What Causes Traffic Congestion?
Congestion has several root causes that can be broken down into two main categories:
n
Excess demand for physical capacity – Put simply, “too many cars on the road.” Just like a pipe
carrying water supply or the electrical grid, there are only so many units that can be moved at a
given time. Transportation engineers refer to this as the physical capacity of the highway system.
Physical capacity is determined by such things as: how many lanes are available to carry traffic, the
curvature of the highway, side clearance, and interchange and intersection design (for example,
length and position of on-ramps and exclusive turning lanes at intersections). Bottlenecks are
locations where the physical capacity is restricted, with flows from upstream sections (with higher
capacities) being funneled into them. This is roughly the same as a storm pipe that can carry only
so much water – during floods the excess water just backs up behind it, much the same as traffic at
bottleneck locations.
n
Traffic-influencing events – In addition to the physical capacity, external events can have a major
effect on traffic flow. These include traffic incidents such as crashes, vehicle breakdowns, work
zones, bad weather and poorly timed traffic signals.
Only recently has the transportation profession started to think of congestion in these terms. Yet it is
critical to do so because strategies must be tailored to address each of the sources of congestion, and they
can vary significantly from one highway to another. Nationally, the best estimates of how much each of
these sources contribute to total congestion are:9
Bottlenecks (Demand/Physical Capacity)…………................ 50% of total congestion
Traffic Incidents……………………………………..….............. 25%
Work Zones………………………………………..……............. 15%
Bad Weather…………………………………………..…............ 10%
Poor Signal Timing…………………………………….............. 5%
Clearly, physical roadway-related bottlenecks are a major part of the national congestion problem.
Further, estimates of the contributions of each congestion source shown above mask the interaction that
physical capacity can have with other traffic events. That is, how much physical capacity exists prior to
the event determines how much impact the traffic incident will have on congestion. Consider a traffic
crash that blocks a single lane on a freeway. That incident has a much greater impact on traffic flow if
only two normal lanes of travel are present than if three lanes are present. Therefore, strategies that
improve the physical capacity of bottlenecks also lessen the impacts of roadway events such as incidents,
weather and work zones.
9
6
http:// www.ops.fhwa.dot. gov/ aboutus/opstory.htm
What Is a Traffic Bottleneck?
T
he layman’s definition of a bottleneck as “too many
cars trying to use a highway at the same time” is
essentially correct. Transportation engineers formalize
this idea as capacity— the ability to move vehicles past
a point over a given span of time. When the capacity of
a highway section is exceeded, traffic flow breaks down,
speeds drop and vehicles crowd together. These actions
cause traffic to back up behind the bottleneck. A more
formal definition of a bottleneck is “an event on or near a
highway, or physical restriction, that causes traffic flow
to degrade from ideal levels.” So, what situations would
cause the overload that leads to traffic backups? We
break these situations down into four types of bottlenecks
for the purpose of discussion.
Type I Bottlenecks – Visual Effects on Drivers. Driver
behavior is a very important part of traffic flow. When
traffic volume is high and vehicles are moving at relatively
high speeds, it may take only the sudden slowing down
of one driver to disrupt traffic flow. Driver behavior in
this case is influenced by some sort of a visual cue and can
include:
n
Roadside distractions – unusual or atypical events
that cause drivers to become distracted from
driving.
n
Limited lateral clearance – drivers will usually
slow down in areas where barriers get too close to
travel lanes or if a vehicle has broken down on the
shoulder.
n
Incident “rubbernecking” – call it morbid curiosity,
but most drivers will slow down just to get a
glimpse of a crash scene, even when the crash has
occurred in the opposite direction of travel or there
is plenty of clearance with the travel lane.
Type II Bottlenecks – Abrupt Changes in Highway
Alignment. Sharp curves and hills can cause drivers to
slow down either because of safety concerns or because
their vehicles cannot maintain speed on upgrades. Another
example of this type of bottleneck is in work zones where
lanes may be redirected or “shifted” during construction.
Both Type I and Type II bottlenecks are usually short-lived
and have a limited effect on traffic flow.
Type III Bottlenecks – Intended Interruption to Flow.
“Bottlenecks on purpose” are sometimes necessary in
order to manage flow. Traffic signals, freeway ramp
meters and tollbooths are all examples of this type of
bottleneck.
Type IV Bottlenecks – Vehicle Merging Maneuvers. This
form of bottleneck has the most severe effect on traffic
flow. Type IV bottlenecks are caused by some sort of
physical restriction or blockage of the road, which in turn
causes vehicles to merge into other lanes of traffic. How
severely a bottleneck influences traffic flow is related to
how many vehicles must merge in a given space over a
given time. Type IV bottlenecks include:
n
Areas where a traffic lane is lost – a “lanedrop”
which sometimes occurs at bridge crossings and in
work zones.
n
Lane-blocking incidents.
n
Areas where traffic must merge across several lanes
to get to and from entry and exit points (called
“weaving areas”).
n
Freeway on-ramps – merging areas where traffic
from local streets can join a freeway.
n
Freeway-to-freeway interchanges – a special case of
on-ramps where flow from one freeway is directed
to another.
For the purposes of this study, only Type IV bottlenecks
related to specific highway features and design are
considered because these lead to the largest amount of
delay. These locations have historically been chokepoints
in the system, and traffic queues there consistently,
especially during weekday rush hours. Incident delay
has been found to be a function of several factors: traffic
volume, available highway space (capacity), characteristics
of incidents (how frequently they occur and how long and
severe they are), and availability of wide shoulders.10
Many of the same improvements that aim to fix physical
bottlenecks can affect these factors as well. For example,
additional lanes increase highway capacity, and transit
or high-occupancy vehicle alternatives can lower traffic
volume. However, these positive effects on reducing
incident delay were not assessed in this study.
10 Cambridge Systematics, Sketch Methods for Estimating Incident-Related Impacts, prepared for the Federal Highway Administration, December 1998.
7
What Can We Do About Traffic Congestion?
Transportation engineers and planners have developed a variety of strategies to deal with congestion.
These fall into several general categories:
1. Increasing the Number and Size of Highways. Adding more lanes to existing highways and building
new ones has been the traditional response to congestion. In some metropolitan areas, however,
it is becoming increasingly difficult to undertake major highway expansions because of funding
constraints, increased right-of-way and construction costs, and opposition from local and national
groups. However, it is clear from observing what has happened since our 1999 study that adding
new physical capacity is an important strategy for alleviating congestion. This often means that
highway designers must think “outside the box” to find creative ways to incorporate new designs
that accommodate all stakeholders’ concerns. Since the worst bottlenecks we have identified are
interchanges, advanced design treatments that spread out turning movements and remove traffic
volumes from key merge areas have been developed, often by using multi-level structures that
minimize the footprint of the improvement on the surrounding landscape.
2. Getting More Out of What We Have. In recent years, transportation engineers have increasingly
embraced strategies that deal with the operation of existing highways, rather than just building
new infrastructure. The philosophy behind transportation operations is to mitigate the effects of
roadway events and to manage short-term demand for existing roadway capacity. Transportation
operations strategies can include the application of advanced technologies using real-time
information about highway conditions to implement control strategies. Referred to as Intelligent
Transportation Systems (ITS), real-time control of highway operations has become a major activity
undertaken by transportation agencies. ITS control strategies take many forms: metering flow onto
freeways, dynamically retiming traffic signals, managing traffic incidents, and providing travelers
with alternative routes and modes. In addition to ITS technologies, other transportation operations
strategies to improve the efficiency of the existing road system have been implemented, including
reversible commuter lanes, movable median barriers to add capacity during peak periods and
restricting turns at key intersections.
The idea behind transportation operations is to increase the efficiency of the existing transportation
infrastructure. That is, roadway events essentially “steal” roadway capacity, and transportation
operations seek to get it back. The deployment of these strategies and technologies is increasing,
and evaluations have shown their impact to be highly cost-effective. However, relying on
transportation operations alone is a limited approach to addressing the congestion problem. A
sound base infrastructure must already exist before transportation operations can be used. Also,
only so much extra efficiency can be squeezed out of an already-stressed highway system.
3. Minimizing Vehicle-Miles of Travel—Travel Demand Management (TDM) and Nonautomotive Travel
Modes. Other approaches to the problem of congestion involve managing the demand for highway
travel. These strategies include putting more people into fewer vehicles (through ridesharing
or dedicated highway lanes for high occupancy vehicles), shifting the time of travel (through
staggered work hours), and eliminating the need for travel altogether (through telecommuting).
The major barrier to the success of TDM strategies is that they require an adjustment in the lifestyles
of travelers and the requirements of employers. Flexible scheduling is simply not possible for a
large number of American workers, which limits the effectiveness of TDM strategies.
Investing in nonautomotive modes of travel—such as rail and bus transit systems and bikeways—
is another strategy for reducing the number of personal use vehicles on the highway system. These
approaches can be a useful supplement to the highway system, particularly for commuter trips.
However, in most metropolitan areas, the level of investment required to meet transportation
demand solely through these means is massive and infeasible. Still, when considered as part of
an overall program of transportation investments, TDM and nonautomotive modes of travel can
contribute substantially to a metropolitan area’s transportation system.
8
4. Managing Urban Growth and Form. The historical cycle of suburban growth has led to an everincreasing demand for travel. Suburban growth was originally fueled by downtown workers
who moved from city centers to the urban fringe to take advantage of lower land prices and
greater social amenities. In the past 20 years, businesses have also moved to the suburbs to be
closer to their employees. This in turn allows workers to live even further away from city centers,
thereby perpetuating suburban expansion. To influence these processes, strategies that attempt
to manage and direct urban growth have been used in several metropolitan areas. These include
land use controls (zoning), growth management restrictions (urban growth boundaries and higher
development densities) and taxation policy (incentives for high-density development). The main
problem with many of these strategies is that they often are contrary to market trends burdening
consumers with extra costs and dampening economic efficiency, at least in the short-run. Unless
a truly regional approach is followed – with cooperation from all jurisdictions within the region
– urban growth may simply be pushed into areas not conforming to growth policies.
It is clear from past experience that no single strategy can adequately address the problem of metropolitan
congestion. However, a balanced, comprehensive approach to traffic congestion can lessen the stifling
gridlock found on many of our highways. Such an approach needs to include improving the convenience
and safety of transit. At the same time, we need to use the roads we already have in the most efficient way
possible. Investing in smart road technologies—such as synchronized traffic lights and computerized
systems to route traffic around congested areas, and options such as reversible commuter lanes and
movable barriers that add road capacity during peak hours of travel— will help. But in many instances, as
highlighted by the projects included in this study, our overstressed road system needs additional capacity
at key points. Providing that capacity by removing strategic bottlenecks as part of an overall program of
congestion relief will reduce the amount of time commuters have to spend on the road, save thousands of
lives, prevent hundreds of thousands of injuries and help us safeguard the environment.
Vehicle Emissions
As vehicles operate, transforming the chemical energy of motor fuel into the kinetic energy of
motion, they produce a number of gases that are by-products of internal combustion. The four
vehicle emissions examined by this study are the most important from a public policy standpoint.
the atmosphere and, in the presence of
ultraviolet light, form smog.
Criteria Pollutants
The Environmental Protection Agency tracks
the emission of six major pollutants, known
as criteria pollutants. Three of the six criteria
pollutants are found in tailpipe emissions. They
are:
n
Carbon monoxide—Carbon monoxide
poses a direct health threat to people by
entering the bloodstream through the
lungs and forming carboxyhemoglobin,
a compound that inhibits the blood’s
capacity to carry oxygen to organs and
tissues.
n
Volatile
organic
compounds—These
emissions mix with nitrogen oxides in
n
Nitrogen oxides—Nitrogen oxides are
the other half of the smog-forming duo
mentioned above.
Greenhouse Gases
Carbon dioxide (CO2) is a natural by-product
of both internal combustion and human
respiration. While not a pollutant, increased
CO2 emissions may affect the Earth’s climate.
Because CO2 is known to trap heat in the
Earth’s atmosphere, it is often referred to as a
“greenhouse gas.”
9
The Relationships:
Why Reducing Congestion Saves Lives, the Environment, Fuel and Time
R
esidents in each of the cities identified as having one of the nation’s worst traffic bottlenecks
would realize substantial benefits—in terms of lives saved, injuries avoided, tailpipe pollutant
and greenhouse gas emissions reduced, decreased fuel consumption and time saved on the average
commute—by fixing those chokepoints.
n
Saving Lives. Popular wisdom often suggests that gridlock can be good for highway safety, based
on the assumption that lower travel speeds lead to a lower risk of serious and fatal crashes.
However, as highway crowding increases and motorists jockey for position at exits and entryways,
the potential for crashes actually increases. Outdated highway design at many bottlenecks can also
lead to serious crashes.
n
Saving the Environment. Congestion is a serious barrier to the nation’s otherwise impressive air
quality progress. Under most conditions, vehicles caught in stop-and-go traffic emit far more
pollutants—carbon monoxide, volatile organic compounds and nitrogen oxides—than they do
when operating without frequent braking and acceleration. However, the relationships between
average vehicle speed and these pollutants can conflict.
Emissions of carbon monoxide and volatile organic compounds decrease as speed increases up to
55 mph and increase very slightly between 55 and 65 mph. Emissions of nitrogen oxides (NOX),
however, decrease as speed increases up to approximately 20 mph, hold steady between 30 and
45 mph, and then increase sharply above 45 mph. Therefore, when a transportation improvement
leads to increases in vehicle speeds, it is possible to decrease levels of carbon monoxide and volatile
organic compounds while increasing emissions of nitrogen oxides. Transportation analysts have
dubbed this phenomenon “The NOX Dilemma,” and it is evident in the improvements studied
in this report. The relationship between levels of NOX and volatile organic compounds in the
formation of ground-level ozone (also known as “smog”) is complex. However, because the
improvements studied also show dramatic decreases in volatile organic compounds, overall smog
levels are expected to improve, especially compared with making no improvements at all.
Vehicles stuck in traffic also increase emissions of carbon dioxide, a greenhouse gas. They emit
CO2 as fuel is consumed. The longer they are delayed in traffic, the more fuel vehicles consume
and, thus, the more CO2 they emit.
n
Saving Fuel. Congestion causes increased fuel use over what would have been consumed if traffic
were flowing smoothly. This is due to less efficient engine operation as well as vehicles taking a
longer time to complete trips.
n
Saving Time. Traffic congestion is a major source of frustration for American travelers. Reducing
road delays eases that frustration and gives motorists more time for families, errands, work or
play. Congestion also has real economic consequences for businesses. Delays in shipments caused
by urban congestion can lead to increased costs for transportation that are ultimately passed on to
consumers.
Because reconstruction often causes additional delays by reducing highway capacity, this
report takes into account projected construction period delays when analyzing the time savings
attributable to improvements at each bottleneck site. To estimate a construction-related delay,
we assume that motorists will lose 20 percent of available highway capacity during the entire
reconstruction period. In reality, state transportation departments endeavor to keep all lanes open
through reconstruction zones as much as possible. Even assuming these construction delays, the
time savings produced by the bottleneck improvements outweigh the additional delays caused by
roadwork.
10
III. EFFECTIVE RELIEF FOR AMERICA’S WORST BOTTLENECKS
EFFECTIVE RELIEF FOR AMERICA’S WORST BOTTLENECKS
T
o identify, rank and assess the nation’s worst bottlenecks, we relied on information provided by
state Departments of Transportation (DOTs) and the cooperation of the American Association of
State Highway and Transportation Officials (AASHTO). All 50 DOTs were asked to identify their
worst bottleneck locations. These candidates were then examined and ranked by analysts at Cambridge
Systematics, Inc. For a more thorough discussion of the methodology, see Appendix A.
Ranking the Bottlenecks
Based on the Cambridge analysis, Table 3.1 displays the 24 worst traffic bottlenecks in the United States,
ranked by total hours of delay.11 The choice of total hours of delay as the ranking criterion implies
that higher traffic volume roadways will be favored. For example, consider two bottlenecks, one with
low volume and one with high volume. Also assume that the relationship between traffic volume
and available capacity is the same at each bottleneck—that is, the unit delay (e.g., minutes of delay
per vehicle) at each site is the same. In this example, total delay will be higher at the higher-volume
bottleneck simply because more vehicles are subjected to congested conditions. Consequently, it would
be ranked higher on our list. We chose this approach because if you were forced to choose which one
should receive improvements, you would select the one with the higher traffic volumes because more
drivers would receive the benefits of the improvement.
A cutoff point of 10 million annual hours of delay was established for identifying bottlenecks for
detailed analysis. Bottlenecks below this cutoff were not studied in detail but are included in the
national-level analysis later in this chapter (see pages 68-69). A total of 24 bottlenecks met the 10 million
hours of delay threshold. Several other bottleneck locations came close to the delay cutoff. Prominent
among them are:
n
I-75 at the I-74 Interchange (Cincinnati, OH): 9,800,000 annual hours of delay
n
I-880 at the State Route-237 Interchange (San Jose, CA): 9,488,000 annual hours of delay
n
I - 71 at the I-75 Interchange (Cincinnati, OH): 9,346,000 annual hours of delay
n
I-4 at the State Route-408 Interchange (East/West Tollway, Orlando, FL): 9,187,000 annual hours
of delay
n
I-35E at the I-30 interchange (“Mixmaster”, Dallas, TX): 9,141,000 annual hours of delay.
It should be noted that other analysis methods, distinct from the methodology employed by this report,
might produce different rankings. Though such alternative analyses might cause some shifting in the
ranking order, we would still expect the locations identified here to show up as severe bottlenecks
because of the solicitation of these locations from local experts and the high-volume nature of these
sites. Still, with such small differences between two adjacent bottlenecks on the list, care must be
exercised before concluding that one location is substantially worse than another.
As a final caveat, congestion is systemic in many of the larger urban areas in the United States.
Entire corridors can operate at unacceptable levels of service (characterized by low speeds over
long distances), and several locations along the corridor can be potential bottlenecks, depending on
daily conditions. The close spacing on interchanges in many areas compound the problem, creating
numerous merging and conflict areas for traffic. In these cases, the one location with the most severe
conditions was identified as the bottleneck. Transportation agencies have recognized the problem of
systemic congestion and have created improvement strategies that treat the entire corridor, rather than a
specific location. Even cases in which a single severe bottleneck can be identified, planned improvements
almost always include improvements to local streets in the bottleneck vicinity and often to interchanges
upstream and downstream from the bottleneck. In the case of systemic congestion in corridors, highway
improvements aimed at the entire corridor, along with transit and demand management strategies, are
often employed.
11 The delay calculations for the rankings do not consider the effect of any current work zones.
11
Table 3.1
America’s 24 Worst Highway Bottlenecks
Annual
Hours of
Delay
Rank
City
Freeway
Location
Vehicles
per Day
1
Los Angeles
US-101
318,000
27,144
2
Houston
I-610
295,000
25,181
3
Chicago
I-90
I-90/94 at I-290 Interchange (“Circle Interchange”)
293,671
25,068
4
Phoenix
I-10
I-10 at SR-51/SR-202 Interchange (“Mini-Stack”)
280,800
22,805
5
Los Angeles
I-405
296,000
22,792
6
Atlanta
I-75
259,128
21,045
7
I-495
243,425
19,429
8
Los Angeles
I-10
318,500
18,606
9
Los Angeles
I-405
318,000
18,606
10
Atlanta
I-285
I-285 at I-85 Interchange (“Spaghetti Junction”)
266,000
17,072
11
Chicago
I-94
I-94 (Dan Ryan Expwy) at I-90 Skyway Split (Southside)
260,403
16,713
12
Phoenix
I-17
I-17 (Black Canyon Fwy) at I-10 Interchange (the
“Stack”) to Cactus Rd.
208,000
16,310
13
Los Angeles
I-5
I-5 (Santa Ana Fwy) at SR-22/SR-57 Interchange
(“Orange Crush”)
308,000
16,304
14
Providence
I-95
256,000
15,340
15
I-495
185,125
15,035
16
Tampa
I-275
I-275 at I-4 Interchange (“Malfunction Junction”)
201,500
14,371
17
Atlanta
I-285
239,193
14,333
18
Seattle
I-5
301,112
14,306
19
Chicago
I-290
I-290 (Eisenhower Expwy) Between Exits 17b and 23a
200,441
14,009
20
Houston
I-45
250,299
13,944
21
San Jose
US-101
244,000
12,249
22
Las Vegas
US-95
US-95 at I-15 Interchange (“Spaghetti Bowl”)
190,600
11,152
23
San Diego
I-805
238,000
10,992
24
Cincinnati
I-75
I-75, from Ohio River Bridge to I-71 Interchange
136,013
10,088
* In reviewing the list of bottleneck locations identified by this report, readers will note that none of the worst
bottlenecks are in the New York City area. As most travelers know, congestion in and around the boroughs of New
York can be significant. However, a very large share of delay in the New York area is related to bridge and tunnel
crossings into Manhattan, most of which are toll facilities. Also, while the New York metropolitan area is laced
with Interstates, parkways, and expressways, they seldom reach the proportions seen in other major areas, except
where multiple highways converge on bridge of tunnel crossings. (A typical lane configuration for a New York area
freeway is six lanes, three in each direction. But there are many of these.) Early in the study, we decided to exclude
toll facilities from our ranking of the worst bottlenecks in the United States. The reason for this exclusion is that toll
facilities are fundamentally different from other physical bottlenecks (such as freeway-to-freeway interchanges) that
are prevalent around the country. Delay comparisons between toll facilities and other types of bottlenecks might not
be consistent since different modeling techniques would be used. If objective field measurements of delay could be
made at all locations around the country, several river crossings into Manhattan would no doubt be included in a list
of the nation’s worst bottlenecks.
12
What Has Changed in the Past 5 Years?
Congestion Has Grown Across the Country . . .
Table 3.1 shows the current rankings of the worst bottlenecks in the country, based on analysis of 2002
data. Since our last report in 1999, traffic nationwide has grown significantly, as documented in the
annual series of Urban Mobility Studies from the Texas Transportation Institute (see the Introduction for
details).
O
ur own analysis also indicates that congestion is continuing to worsen. Table 3.2 shows that for
bottlenecks that were ranked in both this study and our 1999 study, congestion has increased. Some
have grown worse and some have grown worse faster than others. Another indication that congestion
has grown in the past five years is that in the 1999 study, 18 bottlenecks were above a cutoff point of nine
million annual hours of delay. In 2002, 24 bottlenecks were above a higher threshold: 10 million annual
hours of delay.
Considering all potential major bottlenecks throughout the nation experiencing delays of 700,000 annual
hours or more, in 1999 we found a total of 167 bottlenecks (18 considered in-depth, 149 others above the
700,000 hour threshold), while in this study we identify a total of 233 (24 considered in-depth, 209 others).
This represents a 40 percent increase in the number of locations over the delay threshold.
. . . But Improvements Are Possible
Several of the worst bottlenecks identified in the 1999 study have seen substantial improvements,
indicating that success in reducing congestion is achievable. Table 3.2 shows the rankings of the 18 worst
bottlenecks in the 1999 report and where they stand now. Seven of the 18 bottlenecks are no longer
ranked because state DOTs have undertaken reconstruction projects to improve the performance of these
bottlenecks. These locations include:
n
I-93/US-1 Interchange in Boston: The Central Artery. Called the “Big Dig” because of the extensive
tunnel system used in the improvements, the Central Artery is a massive public works project.
A major piece of the tunnel system is now open to traffic. The Northbound Central Artery/I-93
opened on March 29, 2003. Northbound traffic uses a 1.5 mile tunnel below Kneeland to Causeway
streets and emerges to cross the Charles River on the Leonard P. Zakim Bunker Hill Bridge.
n
I-95/I-495 Interchange in Washington: The Springfield Interchange. Known locally as the “Mixing
Bowl,” the Springfield Interchange Improvement Project is scheduled for completion by the end of
2007. The new Springfield Interchange is designed to handle the more than 500,000 vehicles that
are expected to pass through the area each day. Engineers have incorporated advanced designs to
eliminate the dangerous weaving and merging that contribute to both congestion and crashes.
n
SR-55 (Newport Freeway)/SR-22 Interchange in Los Angeles (Orange County). The SR-55/SR-22
interchange was rebuilt with new, wider overcrossings and with a new lane in each direction,
which offers an easier transition between the two freeways. To accommodate the new widened
interchange, the La Veta Avenue overcrossing was also widened. In addition, a general purpose
lane was added on SR-55 between I-405 and SR-91. The California Department of Transportation
(Caltrans) also plans to add a High Occupancy Vehicle (HOV) lane on SR-22 in each direction from
Valley View Street to approximately SR-55. The interchange was rebuilt starting in 1999 and was
completed in 2002.
n
I-290/I-88/I-294 Interchange in Chicago. Dubbed by locals with the grisly moniker the “Hillside
Strangler,” this interchange has been a major source of frustration for Chicago area commuters for
many years. The majority of the construction outlined in our 1999 report has been completed. The
key piece of the construction was the widening of an approximately two-mile stretch eastward
from the point where I-88 merges into I-290 and from where IL-38 eastbound and the I-294 exit
ramps also merge.
13
If state DOTs had not made improvements to these locations, delay would have grown significantly, as
shown in Table 3.3. Note that the increase in delay is much larger than the growth in traffic volumes at
these locations (between 1.0 and 2.5 percent per year). This is due to the nonlinear nature of congestion:
adding more vehicles to an already congested highway adds a disproportionately high amount of
congestion.12
For the three remaining chokepoints removed from the top ranking this year because traffic improvement
projects were either underway or completed by 2002 (the year from which all data analyzed in this study
was collected), we developed the following case studies detailing the impact of bottleneck improvements
at those sites.
Table 3.2 Seven of the 18 bottlenecks identified in 1999 have undergone improvements and are no longer ranked among
the worst bottlenecks in the nation.
Changes Since 1999
1999
Rank
City
Bottleneck
2004 Ranking
1
Los Angeles
I-405 (San Diego Freeway)/I-10 Interchange
Ranked #5
2
Houston
US-59 (SW Freeway)/I-610 Loop Interchange
Reconstruction underway (now nearing
completion); no longer ranked
3
Seattle
I-5/I-90 Interchange
Ranked #17
4
Boston
I-93/US-1 Interchange (Central Artery)
First phase of reconstruction open (2003); no
longer ranked
5
Washington (DC-MD-VA)
I-495 (Capaital Beltway)/I-270 Interchange
Ranked #7
6
I-95/I-495 Interchange (Springfield Interchange)
Reconstruction underway; no longer ranked
7
Los Angeles
US-101 (Ventura Freeway)/I-405 Interchange
Ranked #1
8
Los Angeles
SR-55 (Newport Freeway)/SR-22 Interchange
Not ranked, Caltrans partially reconstructed
1999-2002
9
Los Angeles
I-10 (Santa Monica Freeway)/I-5 Interchange
Ranked #8
10
Albuquerque
I-40/I-25 Interchange (“Big I”)
Major reconstruction completed (2003); no
longer ranked
11
Atlanta
Ranked #10
12
Atlanta
Ranked #6
13
Chicago
I-290/I-88/I-294 Interchange (“Hillside Strangler”)
Reconstruction underway; (majority of
reconstruction completed 2004); no longer
ranked
14
Denver
I-25/I-225 Interchange (“Tech Center Interchange”)
Reconstruction underway; no longer ranked
15
Houston
Ranked #2
16
Not ranked
17
I-95/I-495/US-1 Interchange
Ranked #14
18
Atlanta
Ranked #16
Table 3.3 What Would Have Happened to Improved 1999 Bottlenecks if No Action Had Been Taken
Delay Increases Without Improvements
With No Improvements
14
1999
Rank
City
Bottleneck
2
Houston
4
Boston
6
8
1999 Delay
2004 Delay
% Growth in
Delay
US-59 (SW Freeway)/I-610 Loop Interchange
22,085
28,458
28.9%
I-93/US-1 Interchange (Central Artery)
20,264
25,174
24.2%
Washington, DC (VA)
I-95/I-495 Interchange (Springfield Interchange)
19,629
25,757
31.2%
Los Angeles
SR-55 (Newport Freeway)/SR-22 Interchange
18,049
23,880
32.3%
10
Albuquerque
I-40/I-25 Interchange (“Big I”)
16,029
25,658
60.1%
13
Chicago
I-290 – I-88/I-294 Interchange (“Hillside Strangler”)
12,628
16,441
30.2%
14
Denver
I-25/I-225 Interchange (“Tech Center Interchange”)
11,296
17,992
59.3%
12 The reader may notice that many locations have moved around quite a bit in the rankings comapred to the 1999 study. The main reason
is that traffic growth has an enormous effect on delay estimates, given the nonlinear relationship between congestion and delay. Delay in
areas experiencing high traffic growth will qucikly overwhelm delay in areas with modest traffic growth.
Success Story: US-59 (Southwest Freeway)/I-610 Loop in Houston
The Texas Department of Transportation’s (TxDOT) reconstruction of the I-610 West Loop encompasses
nearly a five-mile stretch of highway, from US-59 (Southwest Freeway) to I-10 Katy Freeway. The reconstruction
includes the renovation of the existing roadway and the addition of new entrances and exits, as well as the creation
of “hot links”: slip ramps (right hand exit ramps providing access to local streets) and frontage roads (auxiliary lanes
separate from the mainline freeway designed for traffic between local streets and freeway interchanges, and to spread
traffic out over a wider area) that provide direct access into and out of local land, while removing traffic from the West
Loop main lanes, helping to dramatically reduce congestion.
West Loop reconstruction is composed of three different projects:
n
Project 1: US-59/ I-610 interchange – COMPLETE.
n
Project 2: West Loop – US-59 to Post Oak Boulevard – UNDER CONSTRUCTION.
n
Project 3: West Loop - Post Oak Boulevard to I-10-Katy Freeway – UNDER CONSTRUCTION.
I
n our 1999 study, we identified this interchange as the
second worst traffic bottleneck in the country. At that
time we did not document any imminent improvements,
although improvement plans were “on the books.”
However, things have progressed rapidly due to
Houston’s high growth rate. As a result, the project took
shape quickly and the improvements to the interchange
have been completed. Even though traffic has grown
from 321,000 vehicles per day on US-59 in 1997 to 339,000
in 2002, we estimate that the total hours of annual delay
have dropped from 22.1 million to 2.9 million as a result
of the interchange improvements alone (including the
addition of access to the new Westpark Tollway; level of
service “D” for the interchange). When the surrounding
improvements are made and the entire area functions at
its target level of service of “C,”13 delay will be reduced
even further.
This project also highlights an important consideration
for improving bottlenecks: the influence of removing the
bottleneck on adjacent roadways. Simply making spot
improvements often releases more traffic downstream –
like opening up the floodgates on a dam. This may result
in transferring the bottleneck to other locations rather than
truly eliminating the problem. As exhibited by TxDOT,
highway designers tend to conceive bottleneck removal
as part of a system problem and will take steps to ensure
that “bottleneck migration” doesn’t occur. In this case,
the addition of the Westpark Tollway and the planned
improvements to the I-10/I-610 interchange are part of
this thinking. Also, the re-working of the frontage road
and land access ramps (“hot links” in TxDOT’s jargon)
helps to manage traffic flow on the main highway.
The entire West Loop project also exhibits further
innovations in DOT practice. During construction,
TxDOT’s work zone policy dictated that:
n
the same number of main lanes be maintained,
and
n
current entrances and exits also be maintained.
T
hough reconstruction projects are often criticized
for producing more congestion through work zones
than the completed project will alleviate, these policies
minimize disruption to existing traffic. Many states have
adopted similar policies and have instituted advanced
traffic control plans during reconstruction to address this
issue. Under these policies, work zones will produce
minor forms of bottlenecks – visual distraction and
reduced side clearance14 – but the impact on traffic flow is
small compared to reducing the number of lanes.
In addition to developing traffic control plans to maintain
these policies, TxDOT (and many other DOTs) use
incentive programs with contractors to complete work
on-time or ahead of schedule. Contractors are given
significant financial incentives/disincentives to complete
the projects in a timely fashion: contractors receive an
extra bonus for every day they finish ahead of schedule
and for every day they are late, a similar amount is levied
in penalty. For example, on the reconstruction of the US59/I-610 interchange ramps, the contractor completed
each ramp ahead of schedule. In fact, interchange work
was scheduled to take 204 days; however, the contractor
completed the project in only 137 days, 67 days ahead of
schedule.
13 Level of service is a concept that traffic engineers have devised to describe how well highway facilities operate. Six levels of service categories are used:
A, B, C, D, E, and F. In layman’s terms, they roughly correspond to the letter grades used in education. On freeways, level of service A is characterized
by free-flow conditions with high vehicle speeds and wide spaces between vehicles. As level of service goes from B to D, speeds stay high, but vehicle
spacing decreases. The physical capacity of the roadway is reached at level of service E; at this level the highest traffic flows are observed and speeds start
to fall off sharply. Level of service F is stop-and-go traffic. Highway designers typically set a goal of level of service C or D for traffic in future years.
14 “Type I” bottlenecks, as discussed in the Introduction
15
Success Story: The “Big I” in Albuquerque
A
s reported in our 1999 study, the
interchange of I-40 and I-25 in downtown
Albuquerque was the 10th worst bottleneck in
the country. So called because it resembles a
giant eye when viewed from the air, the “Big
I” is located near Albuquerque’s downtown
district.
When the Interstate system was
laid out, most routes went directly through
cities and north/south routes often intersect
with east/west routes in the downtown area.
To deal with the problem of getting through
cities during peak periods of congestion,
circumferential highways – “beltways” – have
been constructed around the perimeter of many
cities. Such is not the case in Albuquerque.
When confronted with severe congestion on its
freeways through downtown, the New Mexico
Department of Transportation (NMDOT) opted
to improve the existing roadways rather than
undertake new road construction on its perimeter.
The centerpiece of this improvement was the
reconstruction of the I-40/I-25 interchange.
The “Big I” project entailed the complete
reconstruction of the I-25 and I-40 Interchange
and included 111 lane miles of new road. Ten
bridges were rehabilitated and 45 bridges were
constructed, including eight flyovers that route
drivers between the two interstates. On-ramps of
insufficient length were extended and left-sided
exits were eliminated. The new design also creates
a two-lane frontage road system 30 feet under the
“Big I” to carry an extra 60,000 daily motorists each
way.
Frontage roads are auxiliary lanes physically
separated from the mainline of the freeway. Their
purpose is primarily to collect traffic between local
streets and freeway interchanges. They are used
to remove turning and weaving movements from
the mainline and to spread traffic out over a wider
area. They may also provide access to adjacent
land, though the more common type is used
strictly as an aid to mainline freeway traffic. They
are an integral part of improving highly congested
16
interchanges, and our study uncovered widespread
use in redesigns developed by state DOTs.
D
uring the construction period, traffic
conditions were collected with closed
circuit TV surveillance cameras and sensors,
and disseminated to the public through variable
message signs, the internet and local media.
Between 5:30 a.m. and 9:00 p.m. the contractor
was to maintain two lanes of traffic in all
directions and maintain all ramps that connected
one interstate to another. The entire project was
accomplished in 23 months. So successful was
the on-time performance, work zone management
and public outreach, that the Big I Reconstruction
Project Team was awarded the 2002 President’s
Transportation Award for Highways from the
American Association of State Highway and
Transportation Officials (AASHTO). The award
recognized the team for its positive impact on
transportation nationwide.
We estimate that the total hours of annual delay
has dropped from 16.0 million in 1997 to 1.1 million
in 2002 as a result of the interchange improvements
alone (level of service “C” for the interchange).
These delay numbers include the growth in traffic
at about 2.6 percent per year.
Success Story: I-25/I-225 Interchange in Denver
T
he Southeast Corridor has long been recognized
as one of the Denver region’s highest priority
travel corridors. The corridor follows I-25, the only
north-south freeway in the state, for approximately
14 miles, and I-225, which provides access to I-70, the
region’s major east-west freeway, for approximately
four miles. The Southeast Corridor connects the two
largest employment centers in the region: the Denver
Central Business District, with approximately 112,000
employees in the mid-1990s, and the Southeast
Business District, with approximately 120,000
employees in the mid-1990s. With employment
centers at both ends, the Southeast Corridor is the
highest volume, most congested corridor in the
region. Located approximately in the middle of the
corridor is the I-25/I-225 interchange. According to
Colorado DOT (CoDOT) information, I-25 currently
experiences “severe congestion” for several miles on
either side of the interchange, and I-225 experiences
“moderate congestion.” Although several locations in
this corridor are potential traffic bottlenecks, the I-25/I225 interchange is a major one.
other transit options, a multi-modal approach is being
used to address congestion and safety problems. The
T-REX project involves:
Highway Strategies
n
Adding one through lane in each direction from
Logan Street to I-225 (for a total of four lanes
each way)
n
Adding two through lanes in each direction from
I-225 to the C470/E470 interchange (for a total of
five lanes each way)
n
Reconstructing eight interchanges, including I25/I-225
n
Reconstructing and widening numerous bridges
n
Adding and improving shoulders
n
Improving ramps and acceleration/deceleration
lanes
Transit Strategies
n
Adding 19 miles of double-track light rail
connecting to the existing system at Broadway
in Denver and extending along the west side of
I-25 to Lincoln Avenue in Douglas County and
in the median of I-225 from I-25 to Parker Road
in Aurora
n
Building 13 light-rail stations with Park-n-Rides
at all but one of those stations
n
Adding 34 light-rail vehicles to RTD’s fleet
n
Constructing a new light-rail maintenance
facility in Englewood
I
dentified as the 14th worst bottleneck in our 1999
study, CoDOT has since undertaken a massive
reconstruction project in the I-25 corridor – nicknamed
T-REX (for Transportation Expansion); we reported
that this project was in the planning stages in our
1999 study. The project was initiated in 2001 with an
anticipated completion date of 2006. The T-REX Project
is one of the most extensive multi-modal transportation
projects in the history of Colorado. When the project is
completed in late 2006, the traveling public will have
expanded transportation options and safer highways.
T-REX exhibits the principles we found being applied
to complex bottleneck mitigation projects across the
country: a single solution is rarely effective, but when
multiple strategies are applied real progress can be
made. T-REX is considered by CoDOT to be one
of their next generation transportation projects. By
combining light rail, highway, bike, pedestrian and
In 1999, we estimated that the I-25/I-225 interchange
causes 11.3 million hours of annual delay to motorists.
When the proposed improvements are completed in
2006, we estimate that this will be reduced to 2.0 million
hours of delay without considering any positive effects
from the light rail system. When light-rail is factored
in, the potential exists to reduce delay even further.
17
America’s Worst Bottlenecks and the Benefits of Fixing Them
On the following pages, we detail each of the top 24 worst bottlenecks and show the benefits that
residents in those cities would realize—in terms of lives saved and injuries avoided, tailpipe pollutant
and greenhouse gas emissions reduced, fuel saved and time saved on the average commute—by fixing
those chokepoints.
I
n nine of the 24 cases, transportation officials have identified the location as a serious problem and
have immediate plans to improve traffic flow through the bottleneck. Many of the bottleneck locations
are now under reconstruction (2004) but were not in 2002 when the data were collected, or have specific
design plans that will be implemented by 2005. Where the design is known, the benefits analysis is based
on an estimate of the capacity increase attributable to that design.
The remaining locations have been identified as highly congested locations by transportation agencies,
and most of them have longer-range plans for improvements. However, we did not analyze the effect
of these future improvements, given the uncertainty about design specifics and timing. In these cases
where no specific improvements have been approved, our analysis poses hypothetical improvements
that would bring traffic operations at the bottleneck up to a minimum acceptable level of traffic flow—
technically dubbed “level of service D” by traffic engineers. This analysis is conservative, because traffic
engineers typically design so that level of service D conditions or better will still exist 10 to 20 years in the
future. A three-year construction period is assumed for these cases: 2004 to 2007.
We have chosen to focus solely on the direct benefits experienced by motorists, with the exception
of emissions improvements that have a benefit to all persons in a region. In addition to these direct
benefits, improving congestion will lead to regional and national economic expansion because the cost
of transportation is lowered. This effect has not been included in the analysis, mainly due to lack of
consensus on the exact nature of the relationship. However, it is clear that lower transportation costs will
lead to increased economic activity.
W
e also have not estimated the direct monetary impacts on truck freight. While the dollar value of
travel-time savings to private individuals can be debated, there is little doubt that, particularly to
the trucking industry, time is indeed money. Travel-time savings can be directly traced to savings in the
costs of labor, vehicle operation and lost opportunities due to missing shippers’ deadlines. According
to federal estimates, truck freight tonnage is expected to nearly double between 2000 and 2020. Since
most cross-country freight moves involve a substantial amount of time traveling through or delivering to
urban areas, bottlenecks will be a substantial issue for truck freight.
For each bottleneck, we provide two analyses:
18
n
“Vital Statistics” – a snapshot of current conditions; and
n
“Benefits of Improvements” – the difference in the impact measures between implementing an
improvement and doing nothing.
Vital Statistics
n
n
n
Vehicles per Day. Current and projected
future daily traffic volumes at the
bottleneck. The most recent year for which
complete data on current traffic volumes are
available is 2002. Using the applicable traffic
growth rate for each bottleneck location, we
show projected traffic volumes at each site
in 2025.
Peak Period Delay. The additional time
motorists currently spend stuck in traffic at
this bottleneck, and the delay that will occur
in 2025 at this site if no improvements are
made.
VITAL STATISTICS
Bottleneck Location
Annual Delay: in hours
2002
2025
(estimated)
318,000
Vehicles Per Day
437,396
17.5
Peak Period Delay
(minutes per vehicle per trip)
48.2
(without improvements)
1.40%
Annual Traffic
Growth
Annual Traffic Growth Rate. The percentage
rate by which traffic volumes are projected
to grow annually at the particular bottleneck
location.
Benefits of Improvements
n
n
n
n
Saving the Environment. The cumulative
total reduction in emissions of carbon
monoxide, volatile organic compounds,
nitrogen oxides, and carbon dioxide15 over
the multiyear construction period and the
20-year life of the project.
Saving Time. The peak period delay, with
improvements to the bottleneck and with no
improvements, averaged over the multiyear
construction period and 20-year project life.
Saving Fuel. The amount of fuel saved by
improving congestion at the bottleneck
locations.
Saving Lives. The cumulative total reduction
in crashes, fatalities and injuries over the
multiyear construction period and the 20year life of the project.
SAVING THE ENVIRONMENT
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
898,077
340,317
-62.1
Volatile Organic
Compounds
93,205
39,634
-57.5
Nitrogen Oxides
28,976
27,870
-3.8
Carbon Dioxide
10,910,015
2,377,541
-78.2
SAVING TIME
minutes per vehicle per trip
(averaged over construction period and project life)
No
Improvements
With
Improvements
Percentage
Change
39.6
9.6
-75.8
Peak Period
Delay
SAVING FUEL
Total Fuel Savings (gallons)
875,125,552
Percentage Reduction
78.2%
Savings Per Commuter (gallons over the life of the project)
140.0
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
7,187
29
3,529
15 Note: This analysis does not assume implementation of “Tier II” emissions standards or “Zero Emission Vehicle” requirements in
California, New York, and Massachusetts, although these changes should have little, if any, impact on the percentage change between
emissions with and without improvements to the bottleneck site.
19
1
Los Angeles, California
US-101 (Ventura Fwy) at the I-405 Interchange
Summary
When
the
needed
improvements to the Ventura
Freeway/I-405
interchange
are
implemented,
Los
Angeles residents will realize
significant gains in safety, air
quality and overall quality of
life.
2
101
101
134
134
110
5
27
LOS ANGELES
2
405
101
Wilmar
10
10
1
10
Santa Monica
Like many freeways in Los
Angeles, it is difficult to
distinguish a dominating
physical bottleneck. Long
stretches of highway operate
at similar levels of service (usually poorly)
during peak periods. For that reason, corridoror area-wide strategies, including the addition
of High Occupancy Vehicle (HOV) lanes, transit
improvements, traffic lights on freeway entrance
ramps, and real-time traveler information systems
are employed to address congestion. Such
strategies, combined with the reconfiguration of
the US-101/I-405 interchange, will improve traffic
flow at this site.
Over the 20-year life of the improvements planned
for this interchange, there will be 9,017 fewer
crashes (including 36 fewer fatalities and 4,427
fewer injuries), a 60 percent decrease in smogcausing volatile organic compounds, and an 82
percent decrease in CO2 emissions. In addition,
motorists and truckers traveling through the
interchange during morning or evening rush
hours will shave 25 minutes off their driving time
each trip. For commuters, who typically negotiate
the interchange twice each day, nearly 50 minutes
of commuting time will be saved daily. In
addition, 113 gallons of fuel per commuter will be
saved over the life of the project.
60
19
5
72
110
1
605
405
90
710
Inglewood
1
5
42
42
VITAL STATISTICS
Annual Delay: 27,144,000 hours
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
318,000
17.5
2025
(estimated)
437,396
48.2
1.40%
through reconstruction zones as much as
possible.
Bottleneck Description
The US-101/I-405 interchange is located in the
San Fernando Valley area north of Beverly Hills.
Commuters from the west and north destined for
downtown Los Angeles must pass through this
area. The California Department of Transportation
(Caltrans) District 7 estimates traffic is congested
in this area for nearly five hours every weekday
afternoon.
These figures include the effect of a four-year
reconstruction phase, during which it is assumed
that available highway capacity is reduced by 20
percent every day. In reality, state transportation
departments endeavor to keep all lanes open
20
210
Pasadena
134
5B
Proposed Improvements
Planned improvements at the interchange include:
a) Northbound HOV Lane – A High Occupancy
Vehicle (HOV) lane on the northbound side
of the 405, between Ventura Boulevard and
Burbank Boulevard, is scheduled to break
ground in winter 2004/2005. This extension
will improve traffic flow at the interchange by
increasing capacity. When complete, this HOV
lane will be continuous from Interstate 10 to
Burbank Boulevard.
b) Auxiliary Lane – As commuters travel north on
the 405, past Mulholland Drive and down the
hill into the San Fernando Valley, an auxiliary
lane on the far right of the freeway recently
opened to commuter traffic. An auxiliary
lane exists between on- and off-ramps to ease
merging onto and off of the freeway. This lane
is an extension of the existing on-ramp lane
that begins when you enter the freeway at
Mulholland Drive.
c) Connector Widening, Northbound 405 to
Eastbound 101 – Construction is under way
to add the connector from the northbound 405
to the southbound 101, doubling its capacity.
This project, together with the removal of
cross-traffic with the Gap Closure/Flyunder
Project, will significantly reduce congestion at
the interchange. The project is scheduled to be
completed in the summer of 2004.
d) Reconstructing
the
Connector
from
Southbound 405 to US 101 – An improved
connector from the southbound 405 to both
directions of the 101 is currently in the
planning phase. When funding is secured, this
four-year project will help improve traffic flow
at the 101/405 interchange. Construction could
begin as early as 2009.
e) Extending the Southbound HOV Lane – The
next southbound segment to be constructed
begins at Waterford Street and concludes at
Interstate 10. Groundbreaking is scheduled for
spring 2004 and it is expected to be open and
operating by 2007.
2004-2027
Allowing for a four-year construction period and a 20-year
project life, bringing the US-101 (Ventura Fwy) at the I-405
interchange up to level of service C will significantly reduce congestion, thereby smoothing the flow of traffic and:
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
777,917
284,402
-63.4
Volatile Organic
Compounds
82,642
33,494
-59.5
Nitrogen Oxides
29,159
35,890
23.1*
Carbon Dioxide
8,790,371
1,587,514
-81.9
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
31.4
6.7
-78.8
Peak Period
Delay
SAVING FUEL
738,754,511
81.9%
113.8
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
9,017
36
4,427
* Emissions of carbon monoxide and volatile organic compounds decrease as
speed increases up to 55 mph, and increase very slightly between 55 and 65
mph. Emissions of nitrogen oxides, however, decrease as speed increases up to
approximately 20 mph, hold steady between 30 and 45 mph, and then increase
sharply above 45 mph. Therefore, when a transportation improvement leads to
increases in vehicle speeds, it is possible to decrease levels of carbon monoxide
and volatile organic compounds while increasing emissions of nitrogen oxides.
Transportation analysts have dubbed this phenomenon “The NOX Dilemma,”
and it is evident in the improvements studied in this report. The relationship
between levels of nitrogen oxides and volatile organic compounds in the
formation of ground-level ozone (also known as “smog”) is complex. However,
because the improvements studied also show dramatic decreases in volatile
organic compounds, overall smog levels are expected to improve.
21
2
Houston, Texas
I-610 West Loop at the I-10 (Katy Fwy) Interchange
Summary
When the proposed improvements to the I-610/I-10 interchange are implemented,
Houston residents will realize
10
quality, and overall quality of
life. The Texas Department
of Transportation (TxDOT)
is undertaking a massive
improvement project on the
entire Katy Freeway from the
I-610 interchange westward to
the Fort Bend County line.
261
290
45
610
610
59
10
10
Jacinto City
610
Galena Park
45
59
HOUSTON
90
These figures include the effect of a five-year
possible.
225
610
Bellaire
Over the 20-year life of the improvements planned
for the interchange, there will be 9,362 fewer
crashes (including 37 fewer fatalities and 4,597
fewer injuries), a 60 percent decrease in smogcausing volatile organic compounds, and an 80
percent decrease in CO2 emissions. In addition,
motorists and truckers traveling through the
interchange during morning or evening rush
the interchange once in the morning and once in
the evening, over 54 minutes of commuting time
will be saved each day. In addition, 128.3 gallons
of fuel per commuter will be saved over the life of
the project.
22
90
VITAL STATISTICS
I-610 West Loop at the I-10 Interchange
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
295,000
17.5
2025
(estimated)
442,038
48.2
1.77%
I-610 was Houston’s original “beltway.” With the
construction of the Sam Houston Parkway—a
perimeter highway further out—it now serves as
an inner beltway. I-10, known locally as the Katy
Freeway, is one of the major east-west Interstates,
running from California to Florida. It is also a
major commuter route to downtown Houston
from both the eastern and western suburbs.
As of late 2003, the interchange area is under
complete reconstruction. Highlights include:
a) Reconstruction of 1.08 miles along I-10 and
2.55 miles along I-610
b) Total reconstruction of
Directional Interchange
n
the
Four-Level
Reconstruction of eight (8) “direct
connectors” – ramps that tie directly from
one freeway to another
c) Reconstruction of 14 structures
n
Including bridge structures at Post Oak,
Woodway, Memorial and Buffalo Bayou
d) $263 million project cost with construction
beginning on October 1, 2003
e) Traffic requirements
n
Maintain existing number of lanes
n
Maintain local access across corridor
n
Maintain existing HOV lanes in operation
n
Maintain current ITS (Intelligent Transport
Systems) operations, including variable
message signs, cameras and ramp meters
In addition to the interchange reconstruction,
TxDOT is also adding variable-priced toll lanes in
the center of the Katy Freeway improvement west of
the interchange.
2003-2027
Allowing for a five-year construction period and a 20-year
project life, planned improvements to bring the I-610 at
the I-10 interchange (West) up to level of service C will
significantly reduce congestion, thereby smoothing the
flow of traffic and:
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
882,319
318,119
-63.9
Volatile Organic
Compounds
92,521
36,895
-60.1
Nitrogen Oxides
30,481
36,781
20.7*
Carbon Dioxide
10,389,806
2,040,476
-80.4
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
35.7
8.7
-75.8
Peak Period
Delay
SAVING FUEL
856,341,544
80.4%
128.3
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
9,362
37
4,597
23
3
Chicago, Illinois
I-90/94 at the I-290 Interchange (the “Circle Interchange”)
Summary
If needed improvements
to the “Circle Interchange”
Elmhurst 290
were implemented, Chicago
residents
would
realize
294
88
quality and overall quality
of life. However, because
no specific improvements to
the interchange have been
designed at this time, we
294
analyzed the benefits to be
gained if improvements were
made to bring the interchange
up to a minimum acceptable level of traffic flow
(technically dubbed “level of service D” by traffic
engineers) in the year 2007.
64
64
64
34
20
Maywood
45
83
43
41
90/94
Oak Park
290
CHICAGO
38
Berwyn
Cicero
41
34
55
294
34
43
55
90/94
20
50
83
Level of service is a concept that traffic engineers
have devised to describe how well highway
facilities operate. Six levels of service categories
are used: A, B, C, D, E and F. In layman’s terms,
they roughly correspond to the letter grades used
in education. On freeways, level of service A is
characterized by free-flow conditions with high
vehicle speeds and wide spaces between vehicles.
As level of service goes from B to D, speeds stay
high, but vehicle spacing decreases. The physical
capacity of the roadway is reached at level of
service E; at this level the highest traffic flows
are observed and speeds start to fall off sharply.
Level of service F is stop-and-go traffic. Highway
designers typically set a goal of level of service C
or D for traffic in future years.
For the purposes of this analysis, we have not
attempted to identify a specific combination
of improvements that would ease congestion
at the interchange. Such decisions are properly
made at the state and local level, reflecting
24
41
94
90
VITAL STATISTICS
I-90/94 at the I-290 Interchange
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
293,671
17.5
2025
(estimated)
329,367
24.1
0.50%
the wishes and concerns of the general public,
budgetary priorities, and applicable legal and
regulatory requirements. We have assumed that a
combination of improvements could achieve level
of service D operations, and we have analyzed the
benefits to be gained from such improvements.
Over the 20-year life of the improvements,
there would be 4,869 fewer crashes (including
19 fewer fatalities and 2,391 fewer injuries), a
51 percent decrease in smog-causing volatile
organic compounds, and a 77 percent decrease
in CO2 emissions. In addition, motorists and
truckers traveling through the interchange
during morning or evening rush hours would
shave 17 minutes off their driving time each trip. For
commuters who typically negotiate the interchange
twice each day, nearly 34 minutes of commuting
time would be saved daily. In addition, 72.6 gallons
of fuel per commuter would be saved over the life
of the project.
These figures include the effect of a three-year
through reconstruction zones as much as possible.
The “Circle Interchange” is located in the heart
of downtown Chicago, immediately west of The
Loop – the major downtown business district. The
operation of the interchange itself is complicated by
a series of closely spaced on/off-ramps with local
streets immediately to the north.
2004-2026
Allowing for a three-year construction period and a 20-year
project life, bringing the I-90/94 at the I-290 interchange
(“Circle Interchange”) up to level of service D would
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
470,089
211,886
-54.9
Volatile Organic
Compounds
51,731
25,329
-51.0
Nitrogen Oxides
21,955
25,844
17.7*
Carbon Dioxide
4,673,594
1,091,737
-76.6
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
22.0
5.3
-75.7
Peak Period
Delay
SAVING FUEL
367,369,942
76.6%
72.6
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
4,869
19
2,391
25
4
Phoenix, Arizona
I-10 at the Interchange with State Routes 51 and 202 (the “Mini-Stack”)
Summary
When
needed
improvements to the “Mini-Stack”
interchange are implemented,
Phoenix residents will realize
life. The Arizona Department
of Transportation (AzDOT)
has initiated a $75.7 million
renovation project to modernize State Route (SR) 51 from
Interstate 10 and Shea Boulevard that will positively affect
traffic flow at the interchange.
PHOENIX
60
51
10
10
85
Over the 20-year life of the planned
improvements, there will be 4,236 fewer crashes
(including 17 fewer fatalities and 2,080 fewer
injuries), a 56 percent decrease in smog-causing
volatile organic compounds, and an 88 percent
decrease in CO2 emissions. In addition, motorists
and truckers traveling through the interchange
during morning or evening rush hours will
shave 17 minutes off their driving time each
trip. For commuters, who typically negotiate the
interchange twice each day, nearly 34 minutes of
commuting time will be saved daily. In addition,
74 gallons of fuel per commuter will be saved
over the life of the project.
possible.
26
17
101
202
202
17
VITAL STATISTICS
I-10 at the SR-51 and 202 Interchange
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
280,800
16.7
2025
(estimated)
314,932
22.0
0.50%
Also known as the “Short Stack” (to distinguish
it from its western neighbor, the “Stack”), the
interchange of I-10 with State Routes 51 and 202
is part of a “box” of Interstate highways framing
downtown Phoenix. Within about a four-square
mile area there are three major interchanges (this
one plus two separate ones involving I-10 and
I-17); a tunnel (I-10 under Central Avenue); and
numerous surface street interchanges. From
a traffic standpoint, this makes identifying a
single bottleneck difficult – indeed, any of these
areas could function as a bottleneck on any given
day. Through traffic on I-10 avoids having to
use freeway-to-freeway connectors, but must
negotiate a 90 degree curve.
AzDOT is currently constructing High Occupancy
Vehicle (HOV) lanes on SR-51 and HOV ramps for
the I-10 to SR-51 interchange. Construction of an
elevated ramp to carry the new HOV lanes over
westbound I-10 to the SR-51/Loop 202 interchange
is part of this improvement. Also included is the
construction of new bridges for the HOV ramp, a
new connector road, and the relocated westbound
I-10 exit over Van Buren Street.
2004-2024
Allowing for a one-year construction period and a 20-year
project life, planned improvements bringing the I-10 at
the SR-51/SR-202 interchange (“Mini-Stack”) up to level
of service D will significantly reduce congestion, thereby
smoothing the flow of traffic and:
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
379,470
149,959
-60.5
Volatile Organic
Compounds
42,156
18,631
-55.8
Nitrogen Oxides
18,912
22,673
19.9*
Carbon Dioxide
3,622,016
449,433
-87.6
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
19.6
2.5
-87.3
Peak Period
Delay
SAVING FUEL
325,393,128
87.6%
74.0
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
4,236
17
2,080
27
5
I-405 (San Diego Fwy) at the I-10 Interchange
Summary
Once proposed improvements
to the I-405 corridor are
completed, residents of Los
Angeles will realize gains in
safety, air quality and overall
quality of life.
2
101
101
210
Pasadena
134
5B
110
5
27
Over the 20-year life of the
Santa Monica
planned improvements, there
will be 6,061 fewer crashes
(including 24 fewer fatalities
and 2,976 fewer injuries), a
54 percent decrease in smogcausing
volatile
organic
compounds, and an 80 percent decrease in CO2
emissions. In addition, motorists and truckers
traveling through the interchange during morning
or evening rush hours will shave 20 minutes off
their driving time each trip. For commuters, who
typically negotiate the interchange twice each
day, nearly 40 minutes of commuting time will
be saved daily. In addition, 87.6 gallons of fuel
per commuter will be saved over the life of the
project.
LOS ANGELES
2
405
Wilmar
10
10
60
19
5
72
110
1
possible.
101
10
1
28
134
134
605
405
90
5
710
Inglewood
1
42
42
VITAL STATISTICS
I-405 at the I-10 Interchange
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
296,000
15.8
2025
(estimated)
410,190
35.8
1.43%
I-405, also known as the San Diego Freeway,
connects to I-5 both north and south of Los
Angeles, and is a major access route for the coastal
communities in the Los Angeles area.
I-10 intersects with I-405 only a few miles from its
western terminus in Santa Monica. The University
of California at Los Angeles and Los Angeles
International Airport are in close proximity to
the interchange. The California Despartment of
Transportation (Caltrans) District 7 estimates that
the 11-mile segment of I-405 between I-10 and US101 experiences congestion for almost five hours
every weekday afternoon.
Caltrans plans to construct High Occupancy
Vehicle (HOV) lanes in both directions near the I-10
interchange.
Northbound HOV: The Sepulveda Pass Project will
create a northbound HOV lane on Interstate 405
between National Boulevard (just south of Interstate
10) and Greenleaf Street (just south of US-101). All
work on the project has been suspended. New dates
for circulation of the environmental document and
the projected start of construction are not known
at this time. The project was part of former Gov.
Gray Davis’s traffic Congestion Relief Program - a
$5.3 billion effort to invest in the state’s highway
system.
Southbound HOV: On Feb. 22, 2002, California
officially opened a new, $20.5 million HOV lane in
Los Angeles County – the 7.8-mile southbound I405 lane between the 101 and Waterford Street. The
next southbound segment to be constructed begins
at Waterford Street and concludes at Interstate 10.
The use of additional HOV lanes as a strategy to
reduce congestion throughout the entire I-405
corridor is noteworthy. The major interchanges
are closely spaced and are already constructed
to very high design standards. This means that
making design improvements to one would be very
expensive, as it would involve massive additional
structures. Such improvements may just deliver
additional traffic downstream to the next bottleneck.
Thus, the use of a corridor-wide treatment like HOV
lanes makes sense in this particular case.
2004-2026
project life, bringing the I-405 (San Diego Fwy) at the I-10
interchange up to level of service D would significantly
reduce congestion, thereby smoothing the flow of traffic
and:
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
590,858
245,770
-58.4
Volatile Organic
Compounds
64,137
29,510
-54.0
Nitrogen Oxides
25,348
27,560
8.7*
Carbon Dioxide
6,192,857
1,260,529
-79.6
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
25.1
5.6
-77.6
Peak Period
Delay
SAVING FUEL
505,879,796
79.6%
87.6
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
6,061
24
2,976
29
6
Atlanta, Georgia
I-75 at the I-85 Interchange (“Brookwood Interchange”)
Summary
If needed improvements to
the I-75 and I-85 interchange
were implemented, Atlanta
residents
would
realize
life. The Georgia Department
of
Transportation
(DOT)
20
recognizes the severity of
traffic congestion problems
on these two major freeways,
but no specific improvements
are scheduled for the I-75/
I-85 interchange at this time. Consequently, for
purposes of this report, we analyzed the benefits
to be gained if improvements were made to bring
the interchange up to a minimum acceptable level
of traffic flow (technically dubbed “level of service
D” by traffic engineers) in the year 2007.
Bethesda
75
360
285
Chamblee
141
Smyrna
280
285
19
75
Buckhead
78
139
154
154
Better operations at this interchange might be
achieved through a combination of improvements,
including a redesigned interchange to alleviate
weaving caused by through traffic mixing with
other traffic entering and exiting the highway;
operational controls, such as traffic lights on entry
ramps, to smooth the flow of merging traffic;
the addition of High Occupancy Vehicle (HOV)
lanes; corridor access for bus or rail transit; and
flexible work hours at major employment centers
in the corridor.
30
29
North Atlanta
5
6
85
285
140
236
13
280
278
85
285
42
Stone Mountain
10
Decatur
75/85
155
ATLANTA
139
154
260
20
154
75/85
278
42
VITAL STATISTICS
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
259,128
16.7
2025
(estimated)
510,076
48.2
2.99%
attempted to identify a specific combination of
improvements that would ease congestion at
the interchange. Such decisions are properly
made at the state and local levels, reflecting
Over the 20-year life of the improvements, there
would be 7,187 fewer crashes (including 29
fewer fatalities and 3,529 fewer injuries), a 58
percent decrease in smog-causing volatile organic
compounds, and a 78 percent decrease in CO2
or evening rush hours would shave 30 minutes
off their driving time each trip. For commuters,
who typically negotiate the interchange twice a
day, over one hour of commuting time would be
saved each day. In addition, 140 gallons of fuel
per commuter would be saved over the life of the
project.
These delay numbers include the effect of a
three-year reconstruction phase, during which
it is assumed that available highway capacity is
reduced by 20 percent every day. In reality, state
transportation departments endeavor to keep all
lanes open through reconstruction zones as much
as possible.
2004-2026
project life, bringing the I-75 at the I-85 interchange up to
level of service D would significantly reduce congestion,
thereby smoothing the flow of traffic and:
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
898,077
340,317
-62.1
I-75 and I-85 intersect about three miles north of
downtown Atlanta. This stretch, commonly referred
to as the Downtown Connector, passes through
midtown and downtown Atlanta in a north/south
direction. It is the overlap of I-75, which connects
the region to Michigan to the north and Florida
to the south, and I-85, which connects the region
to Alabama to the southwest and Virginia to the
northeast. The section of I-75/I-85 just south of the
interchange is the third highest volume highway in
the country, experiencing 340,000 vehicles per day.
Volatile Organic
Compounds
93,205
39,634
-57.5
According to the Atlanta Regional Commission’s
2025 Regional Transportation Plan:
[the I-75/85] corridor was identified as
being a congested corridor in the Atlanta
Regional Congestion Management System
(1999 Update). The portions of I-75 and I85 within I-285 on both the north and south
are also Congestion Management System
(CMS) corridors. Since the I-75/85 corridor
already has full Intelligent Transportation
System (ITS) implementation and HOV
lanes and would be extremely difficult to
widen, the CMS report does not identify any
recommended strategies for the corridor.
Solutions to congestion on I-75/85 will
need to be identified and implemented on a
regional basis.
Nitrogen Oxides
28,976
27,870
-3.8
Carbon Dioxide
10,910,015
2,377,541
-78.2
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
39.6
9.6
-75.8
Peak Period
Delay
SAVING FUEL
875,125,552
78.2%
140.0
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
7,187
29
3,529
31
7
Washington, DC
I-495 (Capital Beltway) at the I-270 Interchange
Summary
If needed improvements to the
North Bethesda
270
I-495/I-270 interchange were
95
29
355
193
implemented, residents of the
270
Washington, DC metropolitan
270
495
area would realize significant
495
gains in safety, air quality
495
355
and overall quality of life.
1
410
The Maryland State Highway
193
495
Bethesda
Administration has been
190
D
College Park
AN
studying the entire I-495
YL
410
R
A
M
corridor within Maryland.
Part of the study determined
that variable toll pricing
should be considered. The project is in the early
VITAL STATISTICS
stages and would convert one existing lane and
an additional lane on I-495 into variable toll lanes.
However, it is currently not funded.
D
C
Silver Spring
For this study, it was assumed that no specific
improvements to the I-495/I-270 interchange are
planned for the next five years. Still, the location
remains a high priority, and the Maryland State
Highway Administration recognizes that future
physical improvements may be required. For the
32
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
243,425
16.4
2025
(estimated)
382,230
48.2
1.98%
achieved through a combination of improvements
in the corridor.
made at the state and local levels, reflecting
or evening rush hours would shave 26 minutes off
typically negotiate the interchange twice a day,
more than 50 minutes of commuting time would
project.
I-495, the Capital Beltway, is the beltway for the
Washington, DC area, crossing through both
Maryland and Virginia. I-270 terminates where
it meets I-495 and runs northwest to Frederick,
Maryland. It is a major commuter corridor that
has experienced—and is expected to continue
experiencing—rapid growth. I-270 has two
“branches” where it intersects with I-495; the western
branch is the I-270 spur, which connects with I-495
more than two miles from the main interchange
of I-495 and I-270. Even with this bifurcation,
traffic volumes at the I-495/I-270 interchange are
extremely high. The problem is compounded by the
nearby interchange of Wisconsin Avenue (SR-355).
2004-2026
project life, bringing the I-495 at the I-270 interchange up
to level of service D would significantly reduce congestion,
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
639,846
233,984
-63.4
Volatile Organic
Compounds
67,540
27,853
-58.8
Nitrogen Oxides
23,144
23,642
2.2*
Carbon Dioxide
7,377,028
1,333,213
-81.9
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
32.9
6.7
-79.6
Peak Period
Delay
SAVING FUEL
619,878,414
81.9%
121.2
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
5,942
24
2,918
33
8
I-10 (Santa Monica Fwy) at the I-5 Interchange
Summary
to the I-10/I-5 interchange
were
implemented,
Los
Angeles residents would
realize significant gains in
safety, air quality, and overall
quality of life. The most
recent federal Transportation
Improvement
Program
in
Southern
California
recognizes this interchange as
a congestion area. However,
it does not identify specific
improvements to be undertaken.
2
101
101
210
Pasadena
134
5B
110
5
27
LOS ANGELES
2
405
101
Wilmar
10
10
1
10
Santa Monica
As with many freeways in Los Angeles, it is
difficult to distinguish a dominating physical
bottleneck. Long stretches of highway operate
at similar levels of service (usually poor) during
peak periods. For that reason, corridor- or
area-wide strategies, including the addition of
High Occupancy Vehicle (HOV) lanes, transit
the I-10/I-5 interchange, may work to improve
traffic flow at this site.
The California Department of Transportation
(Caltrans) is currently studying alternatives to
widen the existing six lane I-5 corridor by adding
HOV lanes, and/or general purpose lanes, from
just south of the I-5/I-10 interchange to SR-91.
For this report, no specific improvements
to the interchange are assumed at this time.
However, we analyzed the benefits to be
gained if improvements were made to bring the
interchange up to a minimum acceptable level of
traffic flow (technically dubbed “level of service
34
134
134
60
19
5
72
110
1
605
405
90
5
710
Inglewood
1
42
42
VITAL STATISTICS
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
318,000
12.0
2025
(estimated)
379,909
20.5
0.776%
the interchange. Those decisions are properly
who typically negotiate the interchange once in
the morning and once in the evening, 26 minutes
of commuting time would be saved each day. In
addition, 55.4 gallons of fuel per commuter would
be saved over the life of the project.
The I-10/I-5 interchange is located on the eastern
edge of the City of Los Angeles in an area where
many freeways converge. Dodger Stadium, the
University of Southern California, and the Civic
Center are all in close proximity to the interchange.
Caltrans District 7 estimates that traffic is congested
in this area for four hours every weekday
afternoon.
2004-2026
project life, bringing the I-10 (Santa Monica Fwy) at the
I-5 interchange up to level of service D would significantly
and:
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
448,143
223,166
-50.2
Volatile Organic
Compounds
50,354
27,110
-46.2
Nitrogen Oxides
24,224
28,369
17.1*
Carbon Dioxide
4,052,541
981,953
-75.8
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
16.9
4.3
-74.4
Peak Period
Delay
SAVING FUEL
314,932,095
75.8%
55.4
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
4,116
16
2,021
35
9
I-405 (San Diego Fwy) at the I-605 Interchange (Orange County)
Summary
19
to the San Diego Freeway/
I-605
interchange
were
implemented, Orange County
residents
would
realize
life. The most recent federal
Transportation Improvement
Program
in
Southern
California recognizes the
congestion of this interchange.
However, it does not identify
specific improvements to be undertaken.
Bingham
5
Anaheim
605
55
57
39
405
Orange
5
Garden Grove
22
405
1
Like many freeways in Los Angeles, it is difficult
to distinguish a dominating physical bottleneck.
Long stretches of highway operate at similar levels
of service (usually poorly) during peak periods.
For that reason, corridor- or area-wide strategies,
including the addition of High Occupancy Vehicle
(HOV) lanes, transit improvements, traffic lights
on freeway entrance ramps, and real-time traveler
information systems are employed to address
congestion. Such strategies, combined with the
reconfiguration of the I-405/I-605 interchange,
may improve traffic flow at this site.
Because no specific improvements to the
interchange have been designed at this time,
however, we analyzed the benefits to be gained
if improvements were made to bring the
36
La Palma
22
22
Westminster
Santa Ana
1
5
405
55
VITAL STATISTICS
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
318,000
12.0
2025
(estimated)
356,654
17.5
0.50%
organic compounds, and a 74 percent decrease in
CO2 emissions. In addition, motorists and truckers
who typically negotiate the interchange twice each
day, nearly 22 minutes of commuting time would
project.
2004-2026
project life, bringing the I-405 (San Diego Fwy) at the I-605
and:
The I-405/I-605 interchange is located just east of
the City of Long Beach. The California Department
of Transportation (Caltrans) District 7 estimates
traffic is congested in this area for three hours in the
morning and four hours every weekday afternoon.
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
403,952
211,990
-47.5
Volatile Organic
Compounds
45,795
25,789
-43.7
Nitrogen Oxides
23,206
27,886
20.2*
Carbon Dioxide
3,491,362
907,271
-74.0
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
15.2
4.1
-73.0
Peak Period
Delay
SAVING FUEL
265,034,995
74%
48.4
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
3,590
14
1,763
37
10
Atlanta, Georgia
I-285 at the I-85 Interchange (“Spaghetti Junction”)
Summary
the I-285 and I-85 interchange
were implemented, Atlanta
residents
would
realize
of
Transportation
(DOT)
20
traffic congestion problems
on these two major freeways,
but no specific improvements
are scheduled for the I-285/I85 interchange at this time. Consequently, for
Bethesda
75
360
285
141
Smyrna
280
285
19
75
Buckhead
78
139
154
ramps, to smooth the flow of merging traffic; the
addition of High Occupancy Vehicle (HOV) lanes;
corridor access for bus or rail transit; and flexible
work hours at major employment centers in the
38
85
140
236
13
280
278
154
29
North Atlanta
5
6
85
285
Chamblee
285
42
Stone Mountain
10
Decatur
75/85
155
ATLANTA
139
154
260
20
154
75/85
278
42
VITAL STATISTICS
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
266,000
13.2
2025
(estimated)
340,859
24.6
1.08%
corridor. In fact, the Georgia DOT is planning to
add HOV lanes on I-285 between I-75 and I-85.
improvements that would ease congestion at the
interchange. Such decisions are properly made
at the state and local levels, reflecting the wishes
and concerns of the general public, budgetary
priorities, and applicable legal and regulatory
requirements.
We have assumed that a
emissions than would otherwise occur at this site
without the improvements. In addition, motorists
during morning or evening rush hours would shave
15 minutes off their driving time each trip. For
commuters, who typically negotiate the interchange
once in the morning and once in the evening, 30
minutes of commuting time would be saved each
day. In addition, 66.2 gallons of fuel per commuter
would be saved over the life of the project.
three-year reconstruction phase during which
as possible.
I-285 and I-85 intersect in De Kalb County about 15
miles northeast of downtown Atlanta. I-85 serves
both as a commuter route and as a major intercity
route for the southeastern United States. The area
around the interchange has undergone rapid growth
during the past decade, and this trend is expected to
continue. The Georgia DOT maintains an aggressive
traffic management program on Atlanta freeways,
including surveillance, incident management and
traveler information. The numerous ramps and
flyovers, along with lesser roads that connect at
the interchange, have given rise to the nickname
“Spaghetti Junction,” and local traffic reporters and
travelers refer to it by this nickname.
2004-2026
Allowing for a three-year construction period and a 20year project life, bringing the I-285 at the I-85 interchange
(“Spaghetti Junction”) up to level of service D would
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
430,244
199,983
-53.5
Volatile Organic
Compounds
47,732
24,208
-49.3
Nitrogen Oxides
21,324
24,190
13.4*
Carbon Dioxide
4,127,676
928,781
-77.5
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
19.6
4.8
-75.8
Peak Period
Delay
SAVING FUEL
328,091,755
77.5%
66.2
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
4,178
17
2,051
39
11
Chicago, Illinois
I-94 (Dan Ryan Exressway) at the I-90 Skyway Split (South)
Summary
When needed improvements
to the Dan Ryan Expressway
are implemented, Chicago
residents
will
realize
life.
Elmhurst
64
64
64
290
34
20
Maywood
45
83
43
41
90/94
Oak Park
290
CHICAGO
38
Berwyn
294
Cicero
88
41
34
55
294
improvements, there will be
3,167 fewer crashes (including
294
13 fewer fatalities and 1,555
fewer injuries), a 46 percent
decrease in smog-causing
volatile organic compounds, and a 75 percent
during morning or evening rush hours will
shave 12 minutes off their driving time each
interchange twice each day, nearly 24 minutes of
53.0 gallons of fuel will be saved over the life of
the project.
34
43
55
90/94
20
50
83
possible.
40
41
94
90
VITAL STATISTICS
I-94 at the I-90 Split (South)
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
260,403
13.2
2025
(estimated)
292,056
18.6
0.50%
The Dan Ryan is currently the busiest expressway
in the Chicago area and also has the highest crash
rate. It was first designed and built from 19611963. In 1963, just over 150,000 vehicles traveled
on this roadway each day. Today traffic has more
than doubled to 300,000 vehicles traveling the
expressway daily (north of the interchange on the
coincident I-90/94).
The Illinois Department of Transportation (ILDOT)
will be reconstructing the Dan Ryan Expressway
beginning in 2004 and continuing through 2007.
Major improvements to the Dan Ryan include:
n
All lanes of traffic will be completely
reconstructed for improved travel conditions
from 31st Street south to I-57.
n
Additional local lane in each direction from
47th - 63rd.
n
Additional lane in each direction from
67th - 95th.
n
n
n
n
Full interchange created at 47th Street by
adding northbound exit to 47th street and
southbound entrance from 47th.
Additional updated highway lighting and
overhead message signs.
Enhanced sewers to correct drainage problems
and reduce flooding on the expressway.
Ramps reconfigured to improve traffic
merges and reduce weaving in traffic, both
major causes of accidents on the roadway.
The Skyway Interchange (interchange with I90) has been identified by ILDOT as a major
contributor to congestion and crashes due to its
outdated construction, and entry and exit lanes.
The specific improvements to the interchange are:
a) adding a northbound entrance ramp connecting
to the express lanes and b) relocating the Skyway’s
southbound two-lane exit.
2004-2026
Allowing for a four-year construction period and a 20-year
project life, bringing the I-94 at the I-90 Skyway Split (south
of Chicago) up to level of service D will significantly reduce
congestion, thereby smoothing the flow of traffic and:
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
346,417
175,382
-49.4
Volatile Organic
Compounds
39,040
21,288
-45.5
Nitrogen Oxides
19,086
22,845
19.7*
Carbon Dioxide
3,088,038
770,529
-75.0
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
16.4
4.2
-74.1
Peak Period
Delay
SAVING FUEL
237,693,240
75.0%
53.0
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
3,167
13
1,555
41
12
Phoenix, Arizona
I-17 (Black Canyon Fwy) from I-10 Interchange (“the Stack”) to Cactus Rd.
Summary
to
the
Black
Canyon
Freeway (including the I-10)
interchange (“the Stack”)
101
were implemented, Phoenix
residents
would
realize
of life.
I-17 north of “the
85
Stack” recently underwent a
widening construction project
(additional lanes were added.)
There are also plans to add a
viaduct along I-17, about 6 miles long north of the
I-10 southern terminus, which will be decided by
the Maricopa County voters in May 2004.
42
PHOENIX
60
17
51
10
10
202
202
17
VITAL STATISTICS
I-17 From I-10 to Cactus Road
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
208,000
16.1
2025
(estimated)
233,283
21.5
0.50%
who typically negotiate the interchange twice
each day, nearly 30 minutes of commuting time
would be saved daily. In addition, 63.8 gallons of
fuel per commuter would be saved over the life
of the project.
Completed in May 1990, “the Stack” consists of four
levels, eight ramps, and 347 supporting piers. It is
Arizona’s first fully directional, multilevel freewayto-freeway interchange, and Arizona Highways
called it “practical sculpture in concrete.” I-17
north of “the Stack” has numerous interchanges
with surface streets that compound the problem. In
fact, the merging problems from these interchanges
indicate that there are really a series of bottlenecks
in this corridor, with “the Stack” being one of them
– and our analysis shows that it is the worst of
these. However, given the nature of the bottleneck
“system,” corridor-wide strategies would probably
be the best solution in this particular case.
2004-2026
project life, bringing the I-17 (Black Canyon Fwy) at the I10 interchange (“the Stack”) up to level of service D would
significantly reduce congestion, thereby smoothing the flow
of traffic and:
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
306,236
144,016
-53.0
Volatile Organic
Compounds
34,065
17,375
-49.0
Nitrogen Oxides
15,404
18,270
18.6*
Carbon Dioxide
2,905,693
676,773
-76.7
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
19.3
4.7
-75.8
Peak Period
Delay
SAVING FUEL
228,607,138
76.7%
63.8
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
2,989
12
1,468
43
13
I-5 (Santa Ana Fwy) at the SR-22/SR-57 Interchange (“Orange Crush”)
Summary
If improvements to the
“Orange Crush” interchange
were completed, the people
of Los Angeles would realize
The most recent federal
Transportation Improvement
Program
in
Southern
California recognizes this
interchange as a congestion
area, but it does not identify
specific improvements.
Bingham
5
Anaheim
605
55
57
39
405
Orange
5
Garden Grove
22
405
1
As with many freeways in Los Angeles, it is
difficult to distinguish a dominating physical
bottleneck. Long stretches of highway operate
at similar levels of service (usually poor) during
the “Orange Crush” interchange, may work to
improve traffic flow at this site.
However, for this report, no specific
improvements to the interchange are assumed.
Instead we analyzed the benefits to be gained
44
La Palma
19
22
22
Westminster
Santa Ana
1
405
5
55
VITAL STATISTICS
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
308,000
10.9
2025
(estimated)
443,201
28.1
1.59%
the interchange. Those decisions are properly
compounds, and a 77 percent reduction in CO2
typically negotiate the interchange twice a day, 30
minutes of commuting time would be saved each
day. In addition, 68.5 gallons of fuel will be saved
per commuter of the life of the project.
three-year reconstruction phase during which
as possible.
The “Orange Crush” is probably the most complex
interchange in the U.S. It spans two cities (Orange
and Santa Ana) and is 18 lanes at its peak. Despite
its advanced design, the California Department of
Transportation (Caltrans) estimates that congestion
occurs for five continuous hours every weekday
afternoon.
2004-2026
project life, bringing the I-5 (Santa Ana Fwy) at the SR-22/
SR-57 interchange (“Orange Crush”) up to level of service D
would significantly reduce congestion, thereby smoothing
the flow of traffic and:
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
546,767
254,957
-53.4
Volatile Organic
Compounds
60,422
30,839
-49.0
Nitrogen Oxides
26,490
28,953
9.3*
Carbon Dioxide
5,329,633
1,226,496
-77.0
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
20.2
5.1
-74.8
Peak Period
Delay
SAVING FUEL
420,834,524
77.0%
68.5
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
5,244
21
2,575
45
14
Providence, Rhode Island
Summary
to the I-95/I-195 interchange
are completed, Providence
residents
will
realize
life.
1
95
6
Providence
195
195A
improvements, there would be
1
volatile organic compounds, and a 58 percent
during morning or evening rush hours would
shave nine minutes off their driving time each
interchange twice each day, nearly 18 minutes
of commuting time would be saved daily. In
addition, 40.2 gallons of fuel will be saved per
commuter over the life of the project.
6
Olneyville
10
These figures include the effect of an eight-year
possible.
I-95 and I-195 currently interchange near
downtown Providence. I-195 in the project area
is an antiquated freeway originally constructed
in the late 1950s. It has several sharp curves and
short entrance/exit ramps, which significantly
hamper traffic flow and create numerous unsafe
traffic conflicts. Like many Interstates in older
urban areas, it originally followed existing routes
and alignments, which forced compromises in the
original Interstate design. This led to replacement
46
East Providence
1
VITAL STATISTICS
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
256,000
12.3
2025
(estimated)
287,117
17.8
0.500%
of the original Washington Street Bridge (built to
pre-Interstate standards) in 1968. The current
interchange with I-95 was not completed until
the fall of 1964. The proposed improvement to
I-195 and its interchange with I-95 was chosen to
minimize disruption to historic places and open
space in Providence. It follows an old hurricane
barrier constructed in the 1950s. This alignment
was selected to improve highway safety, reduce
impacts on historic districts, facilitate the
implementation of the city’s Old Harbor Plan (a
redevelopment of the waterfront), preserve India
Point Park, provide improved access to Rhode
Island Hospital, and lessen traffic impact during
construction.
Proprosed Improvements
The interchange of I-95 and I-195 is being physically
moved to a new location. The proposed improvement
includes one mile of brand new highway (I-195) and
1.5 miles of resurfaced and realigned I-95. A total of
15 new bridges are to be built as part of the project,
including numerous ramp bridges and a pedestrian
bridge.
An Intermodal Transportation Center
(bicycles, pedestrians, and commuter boat traffic) is
also being constructed as part of the project, which
is expected to be completed in 2011.
2004-2031
Allowing for a eight-year construction period and a 20-year
level of service C would significantly reduce congestion,
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
415,281
257,776
-37.9
Volatile Organic
Compounds
46,863
30,293
-35.4
Nitrogen Oxides
23,111
29,005
25.5*
Carbon Dioxide
3,676,113
1,542,325
-58.0
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
16.1
7.1
-55.8
Peak Period
Delay
SAVING FUEL
218,850,039
58.0%
40.2
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
3,645
15
1,790
47
15
Washington, DC
I-95 at the Northern Interchange with I-495 (Maryland)
Summary
North Bethesda
270
to the northern I-95/I95
29
355
193
495
interchange
were
270
implemented, residents of the
270
495
Washington, DC metropolitan
495
area would realize significant
495
355
1
410
193
495
Bethesda
The Maryland State Highway
190
D
College Park
AN
Administration has been
YL
410
R
A
M
studying the entire I-495
corridor within Maryland.
Part of the study determined
that variable toll pricing should be considered.
VITAL STATISTICS
The project is in the early stages and would
I-95 Interchange (MD) at I-495
convert one existing lane and an additional lane
on I-495 into variable toll lanes. However, it is
2002
2025
currently unfunded.
(estimated)
D
C
Silver Spring
For the purposes of this report, we analyzed
the benefits to be gained if improvements were
made to bring the interchange up to a minimum
acceptable level of traffic flow (technically
dubbed “level of service D” by traffic engineers)
in the year 2007.
As level of service goes from B to D speeds stay
48
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
185,125
16.7
285,798
48.2
1.91%
in the corridor.
We have not attempted to identify a specific
combination of improvements that would ease
congestion at the interchange. Such decisions
are properly made at the state and local levels,
reflecting the wishes and concerns of the general
public, budgetary priorities, and applicable legal
and regulatory requirements. We have assumed
that a combination of improvements could
achieve level of service D operations, and we
have analyzed the benefits to be gained from such
improvements.
compounds, and an overwhelming 82 percent
an enormous 26 minutes off their driving time
the interchange twice a day, over 50 minutes of
commuting time would be saved daily. In addition,
121.7 gallons of fuel will be saved per commuter
reconstruction phase during which it is assumed
I-95 meets the Capital Beltway (I-495) in Virginia
and tracks with it eastward into Maryland. At a
point roughly 180 degrees from where it entered the
beltway, I-95 veers off northward to Baltimore. The
coincident section of I-95 and I-495 carries a highvolume mix of interstate and commuter traffic. At a
point just before I-95 veers off northward, the total
number of lanes on the coincident section is reduced
from eight to five, leading to extensive congestion.
2005-2026
(MD) up to level of service D would significantly reduce
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
483,125
175,960
-63.6
Volatile Organic
Compounds
50,984
20,928
-59.0
Nitrogen Oxides
17,431
17,878
2.6*
Carbon Dioxide
5,575,292
1,005,743
-82.0
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
33.2
6.8
-79.6
Peak Period
Delay
SAVING FUEL
468,671,773
82.0%
121.7
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
4,525
18
2,222
49
16
Tampa, Florida
I-275 at the I-4 Interchange (“Malfunction Junction”)
Summary
to the I-275/I-4 interchange are
completed, Tampa residents
will realize significant gains in
quality of life.
TAMPA
685
volatile organic compounds,
and an 87 percent decrease in CO2 emissions. In
addition, motorists and truckers traveling through
the interchange during morning or evening rush
the interchange twice each day, 42 minutes of
98.5 gallons of fuel will be saved per commuter
These figures include the effect of a four-year
possible. In fact, this is the stated policy of the
Florida Department of Transportation (FDOT) for
this project; all existing lanes will be kept open
during daylight.
50
574
574
275
685
4
Ybor City
569
41
Gary
Palm River
VITAL STATISTICS
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
201,500
14.7
2025
(estimated)
290,736
39.1
1.61%
The southern terminus of I-4 is at the interchange
with I-275 near downtown Tampa. In 1964,
the western terminus of I-4 was tentatively set
at South Pasadena on the Gulf of Mexico after
following an old rail corridor. This routing was
rejected. In 1967, the interchange with I-75 (now
I-275) was constructed, commonly known now
as “Malfunction Junction.” In 1969, I-75 was
extended west along I-4 into St. Petersburg.
In 1971, the beginning of I-4 was truncated to
“Malfunction Junction” in Tampa. Aside from the
widening/rebuilding project in the late 1990’s, I-4
has not changed since.
FDOT is making capacity and safety improvements
to the I-275/I-4 interchange. As a result of these
operational improvements, eight new bridges will
be constructed, 18 existing bridges will be widened,
and four lanes in each direction will tie into future
projects on each side of this project. The work began
in October 2002 and will be completed in Spring
2006. Improvement highlights for the interchange
include:
n
An increase to four-lanes in each direction.
n
The Ashley Drive entrance ramp will be
extended continuing along I-275 to eastbound
I-4.
n
n
Downtown trips will be physically separated
from through trips by a local auxiliary exit
ramp system.
The flyover ramp from southbound I-275 to
eastbound I-4 will be relocated from the left
to the right side of the highway to reduce
weave movements.
All existing travel lanes are being maintained during
the day.
2004-2026
(“Malfunction Junction”) up to level of service C will
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
419,195
149,443
-64.3
Volatile Organic
Compounds
45,376
18,192
-59.9
Nitrogen Oxides
17,717
22,338
26.1*
Carbon Dioxide
4,437,264
573,356
-87.1
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
25.6
3.9
-84.6
Peak Period
Delay
SAVING FUEL
396,298,267
87.1%
98.5
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
5,264
21
2,585
51
17
Atlanta, Georgia
I-285 at the I-75 Interchange (Northside)
Summary
to the I-285 and I-75
interchange are completed,
Atlanta residents will realize
quality, and overall quality of
of
Transportation
(DOT)
traffic congestion problems on
these two major freeways.
Bethesda
75
360
85
285
Chamblee
141
Smyrna
29
North Atlanta
5
280
285
19
75
Buckhead
78
139
6
285
42
20
Stone Mountain
10
Decatur
155
ATLANTA
154
140
236
13
280
278
85
75/85
139
154
260
20
154
154
planned
improvements,
there will be 4,559 fewer crashes (including 18
compounds, and a 78 percent reduction in CO2
typically negotiate the interchange twice a day, 34
minutes of commuting time will be saved each
day. In addition, 78.3 gallons of fuel will be saved
per commuter over the life of the project.
three-year reconstruction phase, during which
as possible.
52
285
75/85
278
42
VITAL STATISTICS
I-285 at I-75 Interchange (Northside)
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
239,193
12.3
2025
(estimated)
348,595
32.1
1.65%
I-285 serves as the beltway for the Atlanta
region. It intersects with I-75 about 10 miles
from downtown Atlanta. The I-75 corridor north
of the interchange is heavily developed and
is expected to continue growing rapidly. The
Georgia DOT maintains an aggressive traffic
management program on Atlanta freeways,
including surveillance, incident management and
traveler information. The roadways are heavily
instrumented with traffic sensors and cameras.
Several near-term and long-term projects are
planned for this highly congested corridor. In the
near-term, new flyover ramps from I-75 north and
south to I-285 west are being constructed and are
analyzed as part of this study.
In the long-term, the following improvements are
being planned, but funding is not yet available:
n
n
n
I-75: High Occupancy Vehicle (HOV) lanes
from I-285 to Wade Green Road
I-75: Collector/Distributor system from I-285
to Delk Road
I-75/I-285 Interchange: HOV ramps
In addition, a fixed guideway system (light rail)
is being planned for the corridor. It will run from
midtown Atlanta to the Cumberland Mall area in
Cobb County.
For this study, we have estimated the benefits of
only the near-term improvement projects.
2004-2026
project life, bringing the I-285 at the I-75 interchange up
to level of service D will significantly reduce congestion,
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
461,267
203,299
-55.9
Volatile Organic
Compounds
50,475
24,509
-51.4
Nitrogen Oxides
20,935
22,591
7.9*
Carbon Dioxide
4,683,438
1,015,021
-78.3
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
22.6
5.4
-76.1
Peak Period
Delay
SAVING FUEL
376,247,834
78.3%
78.3
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
4,559
18
2,238
53
18
Seattle, Washington
Summary
If traffic operations at the
I-5/I-90 interchange or in
the corridor were improved,
Seattle
residents
would
undoubtedly realize benefits
in terms of safety, air quality,
and time savings. Currently,
the
Washington
State
Department of Transportation
(WSDOT) doesn’t have any
formal plans for the I-5/I90 interchange.
However,
WSDOT conducted an I-5
Operations Study in July 2003 which identified a
potential operational improvement – concluding
that it needs further study. The study identified
two operational improvement concepts for the I5/I-90 interchange area:
n
n
Provide a westbound I-90 connection to
northbound I-5 on the right side of the
mainline
Modify the westbound I-90 to northbound
I-5 connection to the left side of the frontage
roadway.
WSDOT will be conducting an environmental
impact study looking at I-5 improvements through
the Seattle area over the next couple of years
(to be completed in June 2007). The operational
improvements in the 2003 I-5 Operations Study
will be considered.
For the purposes of this report, we analyzed
the benefits to be gained if improvements were
in the year 2007. Level of service is a concept
that traffic engineers have devised to describe
how well highway facilities operate. Six levels
of service categories are used: A, B, C, D, E and
F. In layman’s terms, they roughly correspond to
the letter grades used in education. On freeways,
level of service A is characterized by free-flow
conditions with high vehicle speeds and wide
spaces between vehicles. As level of service goes
from B to D, speeds stay high, but vehicle spacing
54
5
520
513
99
405
SEATTLE
900
Bellevue
90
Newport
Mercer Island
VITAL STATISTICS
2002
Vehicles Per Day:
Peak Period Delay:
Annual Traffic
Growth
301,112
9.8
2025
(estimated)
502,135
48.2
2.25%
decreases. The physical capacity of the roadway
is reached at level of service E; at this level the
highest traffic flows are observed and speeds start
to fall off sharply. Level of service F is stop-and-go
traffic. Highway designers typically set a goal of
level of service C or D for traffic in future years.
in the corridor.
We have not attempted to identify a specific
combination of improvements that would ease
congestion at the interchange. Such decisions
are properly made at the state and local levels,
reflecting the wishes and concerns of the general
public, budgetary priorities, and applicable legal
and regulatory requirements. We have assumed that
a combination of improvements could achieve level
compounds, and an overwhelming 78 percent
an enormous 19 minutes off their driving time
the interchange twice a day, almost 40 minutes of
commuting time would be saved daily. In addition,
90.4 gallons of fuel will be saved per commuter over
the life of the project.
reconstruction phase during which it is assumed
I-5 and I-90 intersect less than two miles from
downtown Seattle. The junction is the western
terminus of I-90, one of the nation’s major eastwest Interstates. Lake Washington limits access to
downtown Seattle from the eastern suburbs, and I90 is one of only two crossings providing this access.
(SR-520 is the other crossing.) The entire I-5 corridor
south of downtown Seattle is routinely congested
in morning and afternoon peak hours. Potential
improvements at the I-5/I-90 interchange and in
the I-5 corridor on either side are constrained by
physical and topographic limitations.
The interchange is elevated, and physical
expansion of the ramps and through lanes would
be very expensive. To deal with this dysfunctional
interchange and with the rest of the corridor,
WSDOT has already instituted aggressive
transportation system management techniques in
the corridor, including HOV lanes, ramp metering,
and incident management.
2004-2026
Allowing for a three-year construction period and a 20year project life, bringing the I-5 at the I-90 interchange in
Seattle up to level of service D would significantly reduce
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
690,560
295,228
-57.2
Volatile Organic
Compounds
74,477
35,397
-52.5
Nitrogen Oxides
28,916
29,840
3.2*
Carbon Dioxide
7,390,287
1,604,222
-78.3
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
25.4
6.1
-75.9
Peak Period
Delay
SAVING FUEL
593,442,582
78.3%
90.4
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
6,278
25
3,082
55
19
Chicago, Illinois
I-290 (Eisenhower Expwy) Between Exit 17b (US-45) and Exit 23a (SR-50)
Summary
the Eisenhower Expressway
were implemented, Chicago
residents
would
realize
quality, and overall quality
of life.
64
64
64
Elmhurst
290
34
20
Maywood
45
83
43
41
90/94
Oak Park
290
CHICAGO
38
Berwyn
294
Cicero
88
41
34
55
294
Like many freeways in very
large metropolitan areas,
it is difficult to distinguish
294
a
dominating
physical
bottleneck. Long stretches
of highway operate at
similar levels of service (usually poorly) during
ramps, and real-time traveler information
systems are employed to address congestion.
Such strategies, combined with the physical
reconstruction of the roadway and interchanges,
may improve traffic flow at this site.
34
43
55
90/94
20
50
83
56
41
94
90
VITAL STATISTICS
I-290 Between Exits 17b and 23a
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
200,411
14.4
2025
(estimated)
224,805
19.2
0.500%
organic compounds, and a 76 percent decrease in
typically negotiate the interchange twice each day,
26 minutes of commuting time would be saved
daily. In addition, 57.4 gallons of fuel will be saved
per commuter over the life of the project.
Unlike the remainder of the top 24 worst bottlenecks
in the country, the cause of traffic problems on
the Eisenhower Expressway cannot be traced to
a single, dominant interchange. Rather, a series
of interchanges with surface streets combined
with extremely heavy and consistent traffic
volumes through the corridor make for a series
of moderate bottlenecks rather than a single large
one. Compounding the problem is the location of
the infamous “Hillside Strangler” (I-88/I-290/I-294
interchange) about two miles west of the section. For
the purpose of analysis, we have picked the worst
of the roadway sections between the interchanges,
which is at about the midway point.
2004-2026
Allowing for a three-year construction period and a 20year project life, bringing the I-290 (Eisenhower Expwy)
between Exits 17b and 23a up to level of service D would
significantly reduce congestion, thereby smoothing the flow
of traffic and:
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
278,345
136,407
-51.0
Volatile Organic
Compounds
31,196
16,520
-47.0
Nitrogen Oxides
14,753
17,593
19.2*
Carbon Dioxide
2,549,849
614,987
-75.9
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
17.6
4.4
-74.9
Peak Period
Delay
SAVING FUEL
198,447,356
75.9%
57.4
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
2,614
10
1,283
57
20
Houston, Texas
I-45 (Gulf Freeway) at the US-59 Interchange
Summary
261
If needed improvements 290
to
the
Gulf
Freeway/
US-59
interchange
were
610
implemented,
Houston
residents
would
realize
10
10
610
of life.
However, other
than a planning study, no
improvements are currently
59
planned at the interchange.
The Houston-Galveston Area
Council (H-GAC), the Texas Bellaire
Department of Transportation (TxDOT), and the
Metropolitan Transit Authority of Harris County
(METRO) have joined together to conduct a
Planning Study to determine future mobility
improvements for the North-Hardy Corridor. The
North-Hardy Corridor stretches approximately 30
miles from downtown Houston to the Woodlands
in Montgomery County, along and between I-45
north and the Hardy Toll Road.
are used: A, B, C, D, E and F. Inlay man’s terms,
58
45
610
90
59
10
Jacinto City
Galena Park
45
HOUSTON
90
225
610
VITAL STATISTICS
I-45 (Gulf Fwy) at US-59 Interchange
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
250,299
11.4
2025
(estimated)
418,801
48.2
2.26%
organic compounds, and an 80 percent decrease in
nearly 45 minutes of commuting time would be
saved daily. In addition, 103.2 gallons of fuel will be
saved per commuter over the life of the project.
2004-2026
project life, bringing the I-45 (Gulf Freeway) at the US-59
and:
The I-45/US-59 interchange is located near the
heart of downtown Houston. The Gulf Freeway
was Houston’s first freeway and was built in 1948
prior to the inception of the Interstate system. The
interchange is not “fully directional” in that it has
several left-hand exits that handle both left and
right turning movements. I-45 runs northwest to
Dallas and southeast to the port of Galveston. US-59
runs southwest to Laredo; it also runs through the
southwest suburbs of Houston, a rapidly growing
part of the region.
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
620,968
249,262
-59.9
Volatile Organic
Compounds
66,305
29,808
-55.0
Nitrogen Oxides
24,370
24,854
2.0*
Carbon Dioxide
6,885,572
1,386,776
-79.9
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
28.4
6.4
-77.5
Peak Period
Delay
SAVING FUEL
563,979,075
79.9%
103.2
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
5,615
22
2,757
59
21
San Jose, California
US-101 at the I-880 Interchange
Summary
101
the US-101/I-880 interchange
were
implemented,
San
Jose residents would realize
significant gains in safety,
Santa Clara
82
air quality, and overall
quality of life. No specific
improvement
has
been
identified for this interchange.
However, corridor- or areawide strategies, including the
addition of High Occupancy
Vehicle (HOV) lanes, transit
could be employed to address congestion. Such
strategies, combined with the reconfiguration
of the US-101/I-880 interchange, may improve
traffic flow at this site.
60
880
680
130
101
880
82
87
San Jose
280
VITAL STATISTICS
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
244,000
10.3
2025
(estimated)
481,555
48.2
3.00%
who typically negotiate the interchange twice each
day, nearly 50 minutes of commuting time would be
saved daily. In addition, 117.7 gallons of fuel will be
saved per commuter over the life of the project.
The US-101/I-880 interchange is located immediately
southeast of the San Jose International Airport. The
California Department of Transportation (Caltrans)
estimates traffic is congested in this area for two and
a half hours every weekday morning and four hours
every weekday afternoon.
2004-2026
project life, bringing the US-101 at the I-880 Interchange up
to level of service D would significantly reduce congestion,
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
749,373
303,151
-59.5
Volatile Organic
Compounds
78,833
35,730
-54.7
Nitrogen Oxides
26,762
26,171
2.2*
Carbon Dioxide
8,723,496
1,955,791
-77.6
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
32.7
8.0
-75.6
Peak Period
Delay
SAVING FUEL
694,123,645
77.6%
117.7
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
6,019
24
2,955
61
22
Las Vegas, Nevada
US-95 at the I-15 Interchange (the “Spaghetti Bowl”)
Summary
to
the
US-95/I-15
interchange are completed,
Las Vegas residents will
realize
significant
gains
in safety, air quality and
overall
quality
of
life.
Apex
157
15
LAS VEGAS
159
decrease in smog-causing volatile organic
typically negotiate the interchange twice each
day, more than 30 minutes of commuting time
would be saved daily. In addition, 68.9 gallons
of fuel will be saved per commuter over the life
of the project.
These figures include the effect of a two-year
possible.
62
93
95
147
515
VITAL STATISTICS
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
190,600
12.0
2025
(estimated)
242,442
23.2
1.050%
US-95 and I-15 intersect just north of the famous
Las Vegas “Strip”.
The “Spaghetti Bowl”
interchange itself was reconstructed from 19972000 at a cost of $92 million. Attention has now
shifted to the immediate west of the interchange on
US-95, which accesses some of the fastest growing
neighborhoods in Las Vegas. (Southern Nevada is
the fastest growing region in the Nation.) As with
many major interchange bottlenecks discussed in
this study, traffic operation is heavily influenced
by nearby surface street interchanges. In this
case, the interchange with Martin Luther King
Boulevard and the Rancho Drive interchanges are
both close enough to provide interference. Both of
these interchanges are slated for improvements.
The “Spaghetti Bowl” interchange is currently
undergoing a $100 million project to construct
ramps and add ramp lanes. Within three years,
a second phase is planned to add more lanes at
the interchange. In addition, there is a five-stage
improvement project on I-95 just west of the
bottleneck. These improvements include:
n
Installing a freeway management system
n
Widening US-95 to ten lanes from Rainbow
Boulevard to I-15
n
n
n
Widening US-95 to six lanes from Craig Road
to Rainbow Boulevard
Widening Summerlin Parkway to six lanes
from Rampart Boulevard to Rainbow
Boulevard
Constructing High Occupancy Vehicle (HOV)
lanes on US-95 and Summerlin Parkway
2003-2025
Allowing for a two-year construction period and a 20-year
project life, bringing the US-95 at the I-15 interchange
(“Spaghetti Bowl”) up to level of service C will significantly
and:
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
276,689
114,009
-58.8
Volatile Organic
Compounds
30,911
14,125
-54.3
Nitrogen Oxides
14,390
18,765
30.4*
Carbon Dioxide
2,571,399
312,765
-87.8
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
18.0
2.4
-86.5
Peak Period
Delay
SAVING FUEL
231,654,731
87.8%
68.9
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
3,524
14
1,730
63
23
San Diego, California
Summary
the I-805/I-15 interchange
were
implemented,
San
Diego residents would realize
life.
8
163
5
8
Because
no
specific
improvements
to
the
interchange
have
been
209
designed at this time, however,
we analyzed the benefits to be
gained if improvements were
in the year 2007.
64
15
SAN DIEGO
805
94
805
15
VITAL STATISTICS
5
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
238,000
9.5
2025
(estimated)
315,787
22.2
1.24%
nearly 25 minutes of commuting time would be
saved daily. In addition, 54.1 gallons of fuel will
be saved per commuter over the life of the project.
I-805 and I-15 meet just east of the San Diego Zoo.
I-805 continues south to the Mexican border and
north to connect with I-5, which continues on to
Los Angeles. Technically, the actual interstate
designation for I-15 begins a few miles north at
I-8; it is known as State Route 15 at this bottleneck
location, though it is a natural extension of I-15.
2004-2026
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
352,853
179,076
-49.2
Volatile Organic
Compounds
39,675
21,799
-45.1
Nitrogen Oxides
19,166
21,823
13.9*
Carbon Dioxide
3,175,212
787,250
-75.2
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
16.4
4.4
-73.2
Peak Period
Delay
SAVING FUEL
244,919,209
75.2%
54.1
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
3,150
13
1,547
65
24
Cincinnati, Ohio
I-75 from Ohio River Bridge to I-71 Interchange
Summary
562
42
71
561
75
CINCINNATI
52
66
OHIO
8
52
75
471
50
Anderson Ferry
50
KY
TUC
KEN
If needed improvements to ICheviot
75 in the vicinity of the Ohio
River Bridge (Brent Spence
Bridge) were implemented,
Cincinnati residents would
Covedale
realize significant gains in
264
quality of life.
Serious
consideration is being given to Delhi Hills
r
8
Rive
replacing the bridge – which
Ohio
connects Ohio and Kentucky.
Villa Hills
The Kentucky Transportation
Cabinet recently presented
six potential concepts for replacing and/or
augmenting the Brent Spence Bridge, but work
is still in the planning stages. Therefore, we have
not assumed any specific improvement at this
location. Instead, we analyzed the benefits to be
gained if improvements were made to bring the
8
VITAL STATISTICS
I-75, Ohio River Bridge to I-71 Interchange
2002
Vehicles Per Day
Peak Period Delay
Annual Traffic
Growth
136,013
15.2
2025
(estimated)
152,546
20.8
0.500%
would be 1,864 fewer crashes (including 7 fewer
fatalities and 915 fewer injuries), a 48 percent
decrease in smog-causing volatile organic
who typically negotiate the interchange twice
each day, nearly 30 minutes of commuting time
would be saved daily. In addition, 60.7 gallons
of fuel will be saved per commuter over the life
of the project.
2004-2026
The Brent Spence Bridge is typical of the cantilever
truss design, with a main span of 830.5 feet and
approach spans measuring 453 feet each. It opened
with six lanes divided between two three-lane
decks. However the emergency shoulders were
eliminated in 1986 and the decks restriped with four
lanes each. Entrance and exit ramps are located at
the immediate ends of the bridge, and their visibility
is poor, especially on the lower deck. The bridge’s
replacement will be built no earlier than 2008, and,
including associated approaches and interchanges,
is currently estimated to cost $750 million. Since
1970, I-71 has been routed over the bridge as well.
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
194,648
93,328
-52.1
Volatile Organic
Compounds
21,731
11,282
-48.1
Nitrogen Oxides
10,042
11,942
18.9*
Carbon Dioxide
1,816,177
429,285
-76.4
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
18.4
4.5
-75.4
Peak Period
Delay
SAVING FUEL
142,245,332
76.4%
60.7
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
1,864
7
915
67
Bottlenecks Nationwide: Benefits Analysis
Summary
In addition to the 24 bottlenecks profiled above, there are many other bottlenecks clogging
freeways throughout the country. The 2002 Highway Performance Monitoring System
(HPMS) data were used to identify these sites, although we have not updated and verified
the data with state transportation agencies.
The HPMS data, including information on the traffic and physical characteristics of the
nation’s highways, are collected by state transportation agencies and reported to the Federal
Highway Administration (FHWA) annually. The data are a basic monitoring tool for FHWA.
They are used to produce the annual trend analyses for FHWA’s publication Highway
Statistics and serve as the basis for the biennial Highway Conditions and Performance report to
Congress. Because the data for these additional locations were not independently verified by
state transportation agencies, conservative assumptions and data checks were used to avoid
overestimating delay and other impacts. Appendix A has a full discussion of the assumptions
and methodology used.
In total, 209 other freeway locations – in addition to the top 24 bottlenecks – were identified
as major chokepoints across the country and are listed in Appendix B. These are locations
where motorists experience more than 700,000 annual hours of vehicle delay. Note that by
comparison, our 1999 study found 167 total bottlenecks compared to 233 identified in this
updated report – a 40 percent increase over the past five years.
Urban Areas with a
Top 24 Bottleneck
Urban Area with
Major Bottlenecks
68
When the effects of improving these 209 additional locations listed in Appendix
B, along with the 24 profiled bottlenecks, are considered, the following results are
obtained for the 20-year benefits period plus the associated reconstruction periods:
emissions (in tons)
No
Improvements
With
Improvements
Percentage
Change
Carbon
Monoxide
49,751,611
22,652,269
-54.4
Volatile Organic
Compounds
5,435,316
2,725,232
-49.8
Nitrogen Oxides
2,296,621
2,518,013
9.7*
Carbon Dioxide
505,572,217
115,457,509
-77.2
SAVING TIME
No
Improvements
With
Improvements
Percentage
Change
Peak Period
Delay
21.6
5.5
-74.5
Total Delay
62,719
14,656
-76.6
(Million vehicle-hours)
SAVING FUEL
40,011,766,000
77.2%
SAVING LIVES
Fewer Total Crashes
Fewer Fatalities
Injury Reduction
449,606
1,787
220,760
* Emissions of carbon monoxide and volatile organic compounds decrease as speed increases up to 55 mph, and
increase very slightly between 55 and 65 mph. Emissions of nitrogen oxides, however, decrease as speed increases up to
approximately 20 mph, hold steady between 30 and 45 mph, and then increase sharply above 45 mph. Therefore, when
a transportation improvement leads to increases in vehicle speeds, it is possible to decrease levels of carbon monoxide
and volatile organic compounds while increasing emissions of nitrogen oxides. Transportation analysts have dubbed
this phenomenon “The NOX Dilemma,” and it is evident in the improvements studied in this report. The relationship
between levels of nitrogen oxides and volatile organic compounds in the formation of ground-level ozone (also known
as “smog”) is complex. However, because the improvements studied also show dramatic decreases in volatile organic
compounds, overall smog levels are expected to improve.
69
SUMMARY AND CONCLUSIONS
T
hrough a combination of soliciting state Department of Transportation opinions and data analysis,
this study has identified the most severe traffic bottlenecks in the country. The study then estimated
the impacts of improving traffic flow in these locations using a methodology that is based on the latest
available delay estimation techniques used in planning analyses, along with available information
on improvements at sites where these are currently planned. The scale of the analysis focused on
individual bottleneck locations and did not consider systemwide impacts. Based on the assumptions
and methodology, the study finds that enormous benefits can be derived from improvements designed
to unclog major freeway bottlenecks. If delay is reduced and the flow of traffic is made smooth at
these specific locations, tailpipe emissions of criteria pollutants can be reduced substantially, and the
number and severity of vehicle crashes can be lessened, saving lives and preventing injuries.
The study also indicates large reductions in carbon dioxide (CO2) emissions at sites where traffic
constrictions are eliminated—an important consideration for those concerned about possible global
climate change. In addition, the potential time savings for motorists and commercial shippers gained by
improving bottlenecks can be substantial, adding—at some of the sites studied—as much as an hour each
day for activities other than sitting in traffic.
IV. SUMMARY AND CONCLUSIONS
A
70
chieving these gains would be valuable but, in many cases, costly. Indeed, for purposes of this study,
we have noted the cost of improvements only in those cases where construction is already under
way or where construction plans are advanced enough that reliable traffic flow estimates and scheduling
can be obtained. In numerous cases, no specific improvements have been identified at the bottlenecks
for the near-term, but nearly all of the worst bottlenecks have long-range improvement plans associated
with them. In these cases we have made a modest assumption about the potential improvements in
order to analyze the effects. What this study does, however, is identify the benefits to be realized if the
bottlenecks are eliminated and, conversely, the price to be paid if nothing is done. For each bottleneck
in each metropolitan area, the state and local officials must weigh the cost of improvements against the
benefits to be gained once the project is complete.
The study used the same methodology and data source as our 1999 study so that trends could be assessed.
Chief among these trends is that congestion has clearly increased in the intervening five years. Delay
at the worst bottlenecks has grown and the
number of locations meeting our criteria for
After revisiting some of the 1999
a bottleneck has increased by 40 percent.
However, after revisiting some of the 1999
bottlenecks, it is clear that success can be
achieved. Seven of the top 18 bottlenecks
identified in 1999 are no longer among the
worst traffic locations in the nation because
of improvements that have been made or
gotten underway in the last five years. The
problem is that these successes have been
overwhelmed by the growth in bottlenecks
elsewhere.
Transportation agencies are
still playing catch-up when it comes to
congestion.
bottlenecks, it is clear that success
can be achieved. Seven of the top 18
bottlenecks identified in 1999 are
no longer among the worst traffic
locations in the nation because of
improvements that have been made
or gotten underway in the last five
years.
This study helps to illuminate the significant benefits that can be obtained by opening bottlenecks on
our most congested freeways. Another key finding of the study is that for onerous bottlenecks, the
benefits of implementing improvements are not negated by the temporary additional delays caused
by reconstruction, based on the assumptions used in this analysis. The study clearly indicates that the
positive effects realized over the life of the completed project outweigh the reduced highway capacity
during the construction phase. The reason for this is clear: These bottlenecks already experience high
congestion delays, and delay increases exponentially with traffic volume. As a result, smoothing the
flow of traffic through these chokepoints produces more dramatic, delay-sensitive benefits than one
might achieve by improvements to other, less congested locations. The effects are even more significant
in areas that are expected to experience rapid traffic growth.
Eliminating the bottlenecks that cause a large portion of delay is the starting point for an effective
congestion management program. Indeed, many other “nonexpansion” strategies—such as improved
operations, Intelligent Transportation Systems (ITS) and High Occupancy Vehicle (HOV) lanes—must
have a functioning highway system as a base. Therefore, when combined with other improvement
tactics, strategic targeting of key bottleneck locations can be a highly effective component of a region’s
overall transportation improvement program.
Operations strategies in particular are targeted to improving the reliability of travel – consistent and
predictable travel times. Sources of congestion such as incidents, weather and work zones contribute
to unreliable travel times and to total delay. This study did not account for the positive effects that
operation strategies can have – we focused on the part of congestion due to limited physical capacity.
However, it must be pointed out that increases in physical capacity will also reduce the amount of
delay due to other sources of congestion. Events such as incidents, weather, and work zones basically
reduce the carrying capacity of a highway. If the base capacity is higher initially, the effect of this
capacity loss will be minimized. Although we have not included this effect in our assessments, it is
definitely present.
T
he study found that many transportation agencies have already adopted this philosophy of
combining highway capital expansion with other strategies to alleviate congestion. Particularly in
the geographically larger metropolitan areas, it is difficult to identify a single “controlling” bottleneck
in a corridor. For example, most of the freeway locations studied in Los Angeles are characterized by
high flows throughout their lengths with no dominant bottleneck area. In these cases, strategies that
target the entire corridor, such as HOV and ITS treatments, have been identified. Long-range plans
in the I-75 and I-85 corridors in Atlanta call for extensive transit service (including fixed guideway),
additional ITS technologies, HOV lanes and selected roadway expansions. In Houston in the I-610/I10 western corridors, highway expansion is coupled with variable-priced tolls to help manage demand
for highway space more efficiently. (Consideration for variable-priced tolls is also being given in the
Washington, DC are are on the Maryland portion of the Capital Beltway [I-495], which has two of the
top 24 worst bottlenecks.)
Even in cases where a dominant bottleneck exists, remediation almost always includes improvements
to the local street system in the vicinity of the bottleneck because improving the bottleneck will
increase traffic through these areas. Also, adjacent interchanges are often key elements of an effort
to alleviate congestion in particular corridors. Transportation agencies realize that congestion is a
complex problem with systemwide implications, and comprehensive mitigation strategies must be
developed to deal with it.
71
APPENDIX A: Methodology
Bottleneck Identification
Interstate highways and other freeways (multi-lane, access-controlled facilities) were the focus of this
report. We limited our consideration to these highways because their traffic volumes are far higher than
those of signalized highways. They are, therefore, locations where the longest delays are likely to occur.
The study used an inclusive approach to identifying potential bottleneck locations. With the cooperation
of the American Association of State Highway and Transportation Officials (AASHTO),16 a brief
questionnaire was sent to all 50 state Departments of Transportation (DOTs) soliciting basic information
about the worst traffic bottlenecks in each state. The following 24 states submitted responses to the
requests for bottleneck information:
ALABAMA
ARIZONA
CALIFORNIA
CONNECTICUT
DELAWARE
FLORIDA
GEORGIA
IDAHO
ILLINOIS
LOUISIANA
MARYLAND
MICHIGAN
MINNESOTA
NEBRASKA
NEVADA
NEW MEXICO
OHIO
OREGON
RHODE ISLAND
SOUTH CAROLINA
TEXAS
VIRGINIA
WASHINGTON
WISCONSIN
T
he responding states represent most of the heavily urbanized states except several in the Northeast
(New York, New Jersey, Pennsylvania, and Pennsylvania) and Michigan. To identify potential
bottlenecks in these and other states, we relied on the results from the previous study conducted in 199917
as well as a scan of the Highway Performance Monitoring System (HPMS) Universe data. HPMS data
are compiled by state DOTs and submitted to the Federal Highway Administration (FHWA) annually.
The data report highway and traffic conditions for every mile of major road in the United States. The data
are broken out by small highway segments, usually defined by significant changes in highway or traffic
conditions. (The average segment length for urban freeways is 0.7 mile.) Sections that had high ratios of
traffic volume to available highway capacity were identified in the data as a preliminary list of candidate
bottleneck sites.
APPENDIX A
Preliminary Ranking
72
From these three sources, candidate bottlenecks were listed in a preliminary ranking, exact locations were
identified from the HPMS data, and a delay estimation was produced by applying a method developed
for FHWA.18 This method has been incorporated into FHWA’s Surface Transportation Efficiency Analysis
Model (STEAM) and Highway Economic Requirements System (HERS) models. The delay estimation
method was developed by running microscopic traffic simulation models to determine basic traffic
parameters, especially for congested traffic flow. These results were then incorporated into a macroscopic
queuing model (QSIM) developed specifically for studying the effects of varying traffic conditions on
delay. QSIM keeps track of traffic queues as they build and dissipate over time. It calculates delay on a
hypothetical highway segment from this queue tracking. It also allows for traffic levels to vary from day
to day. From QSIM runs, a series of equations were developed that predict delay (in terms of hours of
delay per vehicle-mile traveled) as a function of average annual daily traffic (AADT, the average number
of vehicles on a road per day) and highway capacity. Because delay—not speed—is the predicted value,
16 AASHTO is a nonprofit, nonpartisan association representing highway and transportation departments in the 50 states, the District of
Columbia and Puerto Rico. It represents all five transportation modes: air, highways, public transportation, rail and water. Its primary
goal is to foster the development, operation and maintenance of an integrated national transportation system. This study could not have
been conducted without AASHTO’s assistance in coordinating state responses to requests for information.
17 American Highway Users Alliance, Unclogging America’s Arteries: Prescriptions for Healthier Highways, November 1999.
18 Margiotta, Richard, and Cohen, Harry, Improved Speed Estimation Procedures For Use In STEAM and Air Quality Planning, Metropolitan
Planning Division, Federal Highway Administration, June 1998.
delay does not change with assumptions about what the free-flow speed is. Rather, the predicted delay
value is combined with a free flow speed (i.e., speed on the facility under very light traffic conditions; the
ideal speed) to estimate actual speed. Therefore, changing assumptions about what the free-flow speed
is on a facility does not affect the delay estimates or the actual speed estimates. The method is similar in
concept to the one used by TTI in developing national congestion trends, but its development is more
detailed, particularly with regard to queuing.
T
his method provides a consistent basis for comparing locations and doing the rankings. It is not
as detailed as performing traffic simulation at each of the locations or measuring existing delay,
but both of those methods have drawbacks, too. Simulation requires extensive data and testing; it was
deemed impractical for the scope of this study. Measuring delay is extremely costly because of field data
collection and is usually based on a limited number of samples. Separating out the effect of incidents in
field collected delay measurements is highly problematic. Also, many transportation agencies do not
routinely collect field-measured delay, and those that do use varying methods. On the other hand, the
selected method is more sophisticated than the impact analyses traditionally conducted by transportation
planners in long-range planning activities. Therefore, the delay equations discussed above were felt to be
the most appropriate method for this study.
The candidate bottleneck locations were ranked on the basis of total hours of delay by applying the
delay equations assuming that each traffic lane at the location had a capacity of 2,100 vehicles per hour.
(Capacity values were refined in the detailed analysis using the HPMS sample data.) Then, the total hours
of delay were computed by multiplying the equations results by the vehicle-miles traveled (VMT) for the
segment. From the resulting list, the top 30 locations were identified for further analysis.
Note that by emphasizing the total hours of delay, the selection of bottlenecks is directed toward high
volume locations. That is, two bottlenecks may have the same geometric characteristics (number of lanes,
merging areas, etc.), but the one with the higher traffic volume will be ranked higher in our methodology,
simply because more vehicles are exposed to bottleneck conditions. To the individual traveler stuck in
traffic, however, the delay they experience would be the same. However, by focusing on total delay, we
identify locations where potential improvements will have the maximum effect, since more travelers will
benefit from the improvement.
Data Verification
The equations for computing delay depend on the quality of the data used for input. Therefore, for the top
30 preliminary locations, the appropriate state DOTs were contacted to verify the available data, verify
that the location was indeed a bottleneck, obtain any existing information on the location (a schematic
diagram, traffic analysis reports), and identify planned improvements (including design and impact
studies).
Infrequently, states will revise the data after they are submitted, primarily the traffic counts. The reasons
for this include discovery of faulty equipment, discovery of unusual events during the counting period,
and replacing estimated traffic counts in a previous year with better estimates based on current year data.
(Not all locations are measured every year in every state.) This explains why a few locations from the
1999 study have lower traffic volumes in 2002. Such data blips are unavoidable in an analysis such as
presented here, but we believe we have obtained the best information currently available.
Final Ranking Impact Assessments
Based on input from the state DOTs, the final rankings were produced using the methods discussed
above with one refinement. Instead of using the assumed capacity of 2,100 vehicles per lane, the actual
capacity computed from HPMS Sample data for each location was used. From the rankings, the top
bottlenecks were identified for detailed impact assessments, based on a cutoff point of 10 million hours
of delay per year.
73
Impact Assessments
The effect of improving the bottleneck locations was determined using the following procedures and
assumptions:
n
Delay Estimation. The same method for estimating the current delay at the bottleneck locations was
used to estimate delay impacts caused by improvements. Most of the bottleneck locations identified
were freeway-to-freeway interchanges. In all cases, the data identified the problem occurring on one
of the “legs” of the interchange (i.e., the highway referred to as the “Major Route” in the Chapter 2
analyses). Therefore, it was assumed that this “critical leg” was the cause of the delay at the location,
even though this simplifies the actual situation where complex weaving movements may produce
even higher delays. Since the volumes on the “critical leg” are a function of traffic merging from
various ramps, many of the queues may not actually form on the route specified. It is therefore an
indicator that a queuing problem exists in the interchange, but doesn’t specify where the problem
occurs. For design purposes, a more stringent type of analysis is usually undertaken by transportation
agencies. However, a more detailed traffic analysis would require information on traffic volumes and
design criteria for each leg and ramp in the interchange, for both current and forecast years. Such
information is usually developed by transportation agencies only when redesign is being considered.
Most of the locations did not have this level of detail available for this study, particularly in cases
for which design analysis had not been undertaken. Therefore, by focusing on the conditions on the
“critical leg” of the interchange, a consistent method is used for comparing bottlenecks in different
states. In addition, no estimation of incident related delay was made, although it is a major component
of total delay and can be reduced by many of the same improvement types used to alleviate physical
bottlenecks. The net result of these assumptions is to avoid overestimating delay and the other impact
categories.
n
Traffic Growth. The HPMS Sample data were used to identify traffic growth rates on each section.
Data checks were performed and growth rates were not allowed to drop below 0.5 percent per year or
above 3.0 percent per year. (The average growth rate for all urban freeways in the HPMS data is about
2 percent per year.) The same traffic growth rate is applied for both the “no improvement” and “with
improvement” cases. While congestion in the “no improvement” case worsens considerably in future
years, which would tend to suppress traffic growth, no attempt was made to correct for this influence.
Rather, it was assumed that even if the amount of traffic would not materialize on the particular
facility, projected traffic growth still represents demand for transportation in the region and would
have to be accommodated elsewhere.19 Also, traffic was not suppressed during the reconstruction
period, when increased delays would dampen traffic growth or outright reduce it. Finally, the HPMS
growth rates in urban areas are typically based on growth rates developed from MPO travel demand
forecasting models, which do include “elasticity of demand” effects. Because a system-level network
analysis was not performed, it is not possible to say what the net effect of these diverted trips would
be on areawide congestion and travel patterns. However, for high congestion cases, the use of a
maximum delay value and five-mile project length (discussed below) help to offset the problems
caused by assuming a constant growth rate.
n
VMT Estimation. In order to capture adequately the full effect of queuing caused by bottlenecks, a
total highway length must be established over which the impacts are measured. For detailed analysis
of the top ranked bottlenecks, all of which are currently characterized by extensive queuing in the
peak period, a length of five miles was chosen. (A length of five miles was chosen to produce the
initial rankings as well.) In reality, queues at these high volume locations often exceed this distance,
especially as traffic continues to grow. When queuing is present, it is extremely important to select
a constant highway distance over which delay is calculated to capture the full effects on travelers.
The implications of using this five-mile length are to overestimate delays when queues are shorter
19 Increased congestion could also lead to lower economic growth because of increased costs for transportation.
74
than five miles and to underestimate delays when queues are longer. For the purpose of the
rankings, as long as a constant length is used, the order of the bottlenecks would not be changed.
In addition to the delay calculations, VMT is used to scale the various impact categories, which are
usually computed on a per VMT basis (e.g., accidents per VMT, grams of pollutants per VMT). An
abnormally high VMT will produce high estimates of these impacts. However, the focus of this
study is on the relative impacts of improving bottleneck locations and these will not be affected.
n
Criteria Emissions. Generalized relationships between speeds and emission factors for carbon
monoxide, volatile organic compounds, and nitrogen oxides from the MOBILE5a model were
used.20 Although MOBILE5a has now been replaced by MOBILE6, generalized relationships
were not available for this study. Speeds were calculated by combining delay estimates with an
assumed free-flow speed of 60 mph.
n
Fuel Consumption and Carbon Dioxide (CO2). A fuel consumption relationship from HPMS was
used to estimate gallons of fuel as a function of delay21; a factor of 19.5 pounds of CO2 per gallon of
fuel was then applied.22
n
Safety. The total number of crashes was estimated with a relationship that predicts accident rate
as a function of average annual daily traffic (AADT) and capacity.23 Fatalities were estimated by
applying a factor of 0.004 fatalities per crash, and injuries were estimated by applying a factor of
0.491 injuries per crash.24
n
Project Improvements. Many of the bottleneck locations are under reconstruction or have specific
design plans. Where the design is known, an estimate of the capacity increase is made; the revised
capacity is then used to estimate delay. Where no specific improvements have been identified, a
hypothetical improvement is assumed—the scale of this improvement is to increase capacity to
the level at which the facility would be operating at level of service D beginning in the year 2007.
Level of service is a concept that traffic engineers have devised to describe how well highway
facilities operate. Six level-of-service categories are used: A, B, C, D, E, and F. In layman’s terms,
they roughly correspond to the letter grades used in education. On freeways, level of service A is
free-flow conditions characterized by high speeds and wide spaces between vehicles. As level of
service goes from B to D, speeds stay high but vehicle spacing decreases. The physical capacity
of the roadway is reached at level of service E; the highest traffic flows are observed and speeds
start to fall off sharply. Level of service F is stop-and-go traffic. The hypothetical improvement is
nonspecific. Better operations might be achieved through a combination of improvements (e.g., a
redesigned interchange to alleviate weaving caused by through traffic mixing with other traffic
entering and exiting the highway; operational controls, such as traffic lights on entry ramps to
smooth the flow of merging traffic; the addition of HOV (high-occupancy vehicle) lanes; corridor
access for bus or rail transit; or flexible work hours at major employment centers in the corridor).
For the purposes of this analysis, we have not attempted to identify a specific combination of
improvements that would result in improved operations at bottleneck locations. Such decisions are
properly made at the state and local level, reflecting the wishes and concerns of the general public,
20 Science Applications International Corporation, Vehicle Emission Procedures for the Highway Performance Monitoring System, prepared
for the Federal Highway Administration, July 2, 1995.
21 Science Applications International Corporation, Speed Determination Models for the Highway Performance Monitoring System, prepared
for the Federal Highway Administration, October 1993.
22 Transportation Research Board, Toward a Sustainable Future: Addressing the Long-Term Effects of Motor Vehicle Transportation on Climate
and Ecology, National Research Council, Washington, DC, 1997.
23 Cambridge Systematics, New Safety Analysis Procedures for HERS, prepared for the Federal Highway Administration, September 28,
1998.
24 Ibid.
75
budgetary priorities, and applicable legal and regulatory requirements. The level of service D condition
in the year 2007 is considered to be a conservative assumption, because level of service D or better at a
date 10 to 20 years in the future is usually the operational target for highway redesign.
n
Reconstruction Impacts. If a specific improvement has been identified at a location, then the actual
estimated project length is used as the reconstruction period. If no specific improvement was identified,
then a reconstruction period of three years was used (2004 through 2006). Unless otherwise specified by a
state DOT, it was assumed that 20 percent of highway capacity would be lost for the entire reconstruction
period. During the course of the study, we found many cases where state DOTs require that all existing
traffic lanes remain open during peak periods (and sometimes throughout the day). However, so as not
to overstate benefits, we assumed a 20 percent capacity reduction for all location studied.
n
Peak Period. In addition to daily numbers, delay is also reported by peak period, which is defined as
three hours in the morning (7 to 10 AM) and three hours in the afternoon (4 to 7 PM). It is important
to select multiple hours to capture the effects of queuing. Delays—in terms of minutes of delay per
vehicle—are reported for the entire six-hour peak period. For example, if the peak period delay is found
to be 10 minutes per vehicle, this means that every vehicle traveling through the bottleneck during
these six hours experiences 10 minutes of delay. For the five mile project length, the 10 minutes of delay
translates to an average peak period speed of around 20 mph. In terms of daily trips by commuters,
assuming they must go through the bottleneck both morning and evening and with an average of 1.2
persons per vehicle, each commuter trip would experience 10 minutes x 2 trips x 1.2 persons per vehicle,
or 24 minutes of delay per vehicle. To make estimates conservative, it is assumed in the reporting that
vehicle occupancy is 1.0. In other words, all delay is reported strictly on a vehicle basis rather than a
person basis.
n
Analysis Period. The impact analyses begin in year 2004. (Adjustments are made to account for locations
that are currently under construction or not expected to be under construction until sometime beyond
2004.) First, impacts are accumulated for the reconstruction period. When that is completed, a 20-year
project life is used. Therefore, the forecast period for each project is different depending on the length of
the reconstruction period. For the total period, impacts with and without the improvement are calculated
year-by-year. Each year, traffic is incremented by the growth rate. It should be noted that in high-growth
areas this produces very high values for the AADT-to-capacity ratio in the delay equations for the “do
nothing” base case. The ratio was capped at a value of 24, ignoring any additional delay beyond that
point. This value implies that speeds on the five-mile segment do not drop below five mph. The final
reported statistics are the net impacts, considering that there will be a degradation in performance
during the reconstruction period.
n
System-Level Effects. The impact assessment was focused on the specific facilities and system effects
were not assessed. A comprehensive analysis of all the impacts of these types of major projects would
involve using each metropolitan area’s network level travel demand models and network level
transportation economic analysis models, such as STEAM.
National-Level Analysis
An additional number of freeway bottleneck locations were identified in the HPMS data by selecting locations
that had 700,000 or more annual hours of delay, based on applying the delay model discussed above. The
same procedures as used for the individual bottleneck locations were applied to estimate impacts. Because
the data had not been verified by transportation agencies, four assumptions were used in the analysis to avoid
overestimating delay and other impacts:
1. The AADT-to-capacity ratio was capped at 16. This number was based on the fact that the highest ratio
for the top ranked bottlenecks was 18.
76
2. An assumed project length of two miles was used as opposed to a five-mile length for the top
ranked bottlenecks. In addition to producing lower estimates of delay, these locations are not as
severe bottlenecks as the top ranked locations. Therefore, queue lengths are expected to be shorter,
justifying the shorter segment length.
3. Only one location was selected for each highway in a county within an urban area to avoid double
counting with the HPMS data. The selection was based on taking the highway section with the
highest AADT-to-capacity ratio.
4. The hypothetical three-year level of service D in year 2007 improvement was used to estimate
impacts, which were accrued over the three-year reconstruction period (2004 through 2006) plus a
20-year project life.
Discussion
Two limitations of the methodology are the lack of system-level analysis of impacts and the use of a
constant traffic growth rate for the “no-improvement” and “with-improvement” cases. Because proper
assessment of these two items would require a detailed system analysis using network models and
economic analysis tools, this could not be done within the scope of the study. In light of these limitations,
care was taken not to overstate expected benefits in the analysis by:
n
Not allowing delay to grow beyond a maximum level for the “no-improvement” case.
n
Focusing the analysis on the “critical leg” of the bottleneck for interchanges, recognizing that traffic
on other parts of the interchange are not subjected to the delay in the analysis.
n
Measuring delay over a constant five-mile highway segment for all cases, acknowledging that
much longer queues can result, particularly for future years under the “no-improvement” case.
n
Focusing solely on congestion due to the characteristics of traffic flow through the physical
bottleneck (“recurring delay”), rather than adding in the delay due to incidents, which would
also be likely to be reduced with improvements. For the analysis, traffic growth was assumed to
be constant for both the “with-improvement” and “no-improvement” cases. For severe existing
bottlenecks, future traffic growth will tend to be suppressed if no improvements are made.
However, given the difficulties of determining this effect without a detailed system-level network
analysis, a constant growth rate was used. The points made above at least partially compensate
for this effect, particularly the delay cap. In addition, if congestion does indeed suppress
traffic growth, then it would also be suppressed for the “with-improvement” case during the
reconstruction period as existing travelers adjust their schedules, routes, and modes; this was also
not addressed. Finally, in the case where expected growth of traffic on a facility is suppressed by
congestion on that facility, trips will be diverted elsewhere. It is not possible to determine this
effect without a system-level network analysis, which was beyond the resources available for this
project. Depending on the characteristics of the transportation network in individual cases, these
diverted trips may be subjected to congestion elsewhere and/or make circuitous routes to their
destinations. The analysis also considered the increased delay, emissions, and crashes during a
construction period. During this period, a capacity decrease of 20 percent for the entire period was
used. This number was determined by considering that construction effects will vary from minimal
to significant on a “critical leg” and that agencies implementing major reconstruction projects try
to maximize the number of lanes kept open to traffic. In practice, if agencies do not design projects
and traffic mitigation plans so as to minimize disruptions, construction period impacts could be
greater.
77
APPENDIX B: Major Bottlenecks State-by-State
Arizona
Vehicles/Day
2002 Delay
Urban Area
County
Route
Location
Phoenix
Maricopa, AZ
Interstate 17
I-17 (Black Canyon Fwy) between I-10 and
Cactus Rd.
208,000
16,310
Phoenix
Maricopa, AZ
Interstate 10
I-10 at SR-51/SR-202 Interchange (“MiniStack”)
280,800
22,805
Phoenix
Maricopa, AZ
Interstate 10
I-10 at I-17 Interchange West (the “Stack”)
228,800
2,671
Phoenix
Maricopa, AZ
US–60
US-60 (Superstition Fwy) Loop-101 to I
- 10
166,400
1,711
Phoenix
Maricopa, AZ
State Route 101
Loop-101 Agua Fria at 67th Ave to I - 17
112,320
1,232
Phoenix
Maricopa, AZ
State Route 202
Loop-202: Dobson to I - 10
218,400
2,099
Urban Area
County
Route
Location
AntiochPittsburgh
Contra Costa, CA
State Route 4
SR-4 at Willow Pass Rd
124,000
1,987
Los Angeles
Los Angeles, CA
US–101
318,000
27,114
Los Angeles
Los Angeles, CA
Interstate 405
296,000
22,792
Los Angeles
Orange, CA
Interstate 405
318,000
18,606
Los Angeles
Los Angeles, CA
Interstate 10
318,500
18,606
Los Angeles
Orange, CA
Interstate 5
I-5 (Santa Ana Fwy) at SR-22/57
Interchange (“Orange Crush”)
308,000
16,304
Los Angeles
Los Angeles, CA
State Route 60
I-710 at Whittier Blvd
245,000
3,748
Los Angeles
Los Angeles, CA
State Route 60
SR-60 at I-605 interchange
223,000
2,370
Los Angeles
Los Angeles, CA
State Route 91
San Gabriel River Frwy
283,000
3,204
Los Angeles
Los Angeles, CA
Interstate 105
I-105 at US-107 Interchange
230,000
2,767
Los Angeles
Los Angeles, CA
Interstate 110
I-110 at Saulson Ave
320,000
5,585
Los Angeles
Los Angeles, CA
State Route 134
SR-134 at SR-2 Interchange
238,000
3,293
Los Angeles
Los Angeles, CA
Interstate 710
Long Beach Frwy
237,000
3,193
Los Angeles
Orange, CA
Interstate 5
(“El Toro”)
356,000
6,460
Los Angeles
Orange, CA
State Route 57
US-57 at US-91
279,000
2,965
Los Angeles
Orange, CA
State Route 91
Orange Frwy
234,000
4,632
Los Angeles
San Bernardino, CA
Interstate 10
San Bernardino Frwy
258,000
4,682
Riverside-San
Bernardino
Riverside, CA
State Route 91
SR-91 at I-215 Interchange
264,000
2,198
Riverside-San
Bernardino
Riverside, CA
Interstate 215
Pomona Frwy: SR-91 Interchange
168,000
1,785
Sacramento
Sacramento, CA
State Route 99
SR-99 at Stockton Blvd
172,000
2,069
San Diego
San Diego, CA
Interstate 805
238,000
10,992
San Diego
San Diego, CA
Interstate 5
I-5 at SR-56 Interchange
225,000
2,469
San Diego
San Diego, CA
Interstate 8
Mission Valley Frwy
248,000
2,467
San Diego
San Diego, CA
Interstate 15
I-15 at SR-78 Interchange (Escondido)
202,000
1,325
San FranciscoOakland
Alameda, CA
Interstate 80
I-80 at Central St
259,000
4,700
Alameda, CA
Interstate 238
I-238 at I-550
119,000
1,647
(Thous. Hours)
APPENDIX B; Major Bottlenecks State-by-State
California
78
Vehicles/Day
2002 Delay
(Thous. Hours)
Alameda, CA
Interstate 580
I-580 MP 17-19
189,000
906
Alameda, CA
Interstate 880
I-880 at I-238
271,000
5,449
Contra Costa, CA
Interstate 680
I-680 at US-13
170,000
1,925
San Francisco, CA
State Route 80
SR–80 at US-101 Interchange
218,000
2,096
San Francisco, CA
US–101
251,000
4,113
San Mateo, CA
US–101
US-101 at SR-92 Interchange
253,000
4,326
San Mateo, CA
Interstate 280
221,000
2,273
Santa Clara, CA
Interstate 880
184,000
2,815
San Jose
Santa Clara, CA
US–101
244,000
12,249
Santa Cruz
Santa Cruz, CA
State Route 1
110,000
1,094
Urban Area
County
Route
Location
Denver
Adams, CO
Interstate 25
US-87 at US-36
237,839
4,782
Denver
Arapahoe, CO
Interstate 225
I-225 at Leetsdale Dr
112,202
1,231
Denver
Denver, CO
Interstate 70
I-70 at I-25 Interchange (“Mousetrap”)
151,030
3,037
Denver
Denver, CO
Interstate 225
112,202
1,231
Denver
Adams, CO
Interstate 25
US-87 at US-36
237,839
4,782
Denver
Arapahoe, CO
Interstate 225
112,202
1,231
Denver
Denver, CO
Interstate 70
I-70 at I-25 Interchange (“Mousetrap”)
151,030
3,037
Denver
Denver, CO
Interstate 225
112,202
1,231
Colorado
Vehicles/Day
2002 Delay
(Thous. Hours)
Connecticut
Vehicles/Day
2002 Delay
Urban Area
County
Route
Location
HartfordMiddletown
Hartford, CT
Interstate 84
I-84 at SR-2 Interchange (“Mixmaster
East”)
140,500
2,825
New HavenMeriden
Fairfield, CT
Interstate 95
146,300
806
New HavenMeriden
New Haven, CT
Interstate 91
93,900
1,539
New HavenMeriden
New Haven, CT
Interstate 95
139,600
1,484
HartfordMiddletown
Hartford, CT
Interstate 84
I-84 at SR-2 Interchange (“Mixmaster
East”)
140,500
2,825
New HavenMeriden
Fairfield, CT
Interstate 95
146,300
806
New HavenMeriden
New Haven, CT
Interstate 91
93,900
1,539
New HavenMeriden
New Haven, CT
Interstate 95
139,600
1,484
(Thous. Hours)
Delaware
Urban Area
County
Route
Location
Philadelphia (PA-NJ)
New Castle, DE
Interstate 95
Vehicles/Day
199,677
2002 Delay
(Thous. Hours)
1,256
79
District of Columbia
Vehicles/Day
2002 Delay
Urban Area
County
Route
Location
Interstate 695
I-695 at S. Capitol St
111,030
1,142
Interstate 95
I-95 at Mt. Vernon Memorial
170,000
1,925
(Thous. Hours)
Florida
Vehicles/Day
2002 Delay
Urban Area
County
Route
Location
Jacksonville
Duval, FL
Interstate 10
I-10 at US-17A Interchange
135,500
2,725
Jacksonville
Duval, FL
Interstate 95
168,000
3,378
Miami-Hialeah
Broward, FL
State Route 112
(MP 0.000)
95,735
1,671
Miami-Hialeah
Broward, FL
State Route 821
SR-821 near SR-817
144,300
2,901
Miami-Hialeah
Broward, FL
State Route 826
154,000
3,097
Miami-Hialeah
Broward, FL
State Route 836
SR-836 between I-95 and I-395
137,500
2,765
Miami-Hialeah
Broward, FL
State Route 874
SR-874 near SR-821
111,500
1,185
Miami-Hialeah
Broward, FL
US–441
US-441 near SR-383
78,500
1,578
Miami-Hialeah
Broward, FL
Interstate 95
296,000
5,952
Miami-Hialeah
Broward, FL
Interstate 595
Florida Tpke at I-595
179,500
2,484
Miami-Hialeah
Palm Beach, FL
Interstate 95
I-95 at Golden Glades Interchange
179,500
2,484
183,000
2,733
(Thous. Hours)
Orlando
Orange, FL
Interstate 4
I-4 at SR-408 Interchange (East/West
Toll)
Orlando
Osceola, FL
Interstate 4
US-192 at I-4
109,423
1,052
Tampa
Hillsborough
Interstate 275
I-275 at I-4 Interchange (“Malfunction
Junction”)
201,500
14,371
Georgia
Vehicles/Day
2002 Delay
Urban Area
County
Route
Location
Atlanta
Fulton, GA
Interstate 75
259,128
21,045
Atlanta
DeKalb, GA
Interstate 285
I-285 at I-85 Interchange (“Spaghetti
Junction”)
266,000
17,072
Atlanta
Cobb, GA
Interstate 285
I-285 at I-75
239,193
14,333
Atlanta
De Kalb, GA
Interstate 20
179,300
2,481
Atlanta
De Kalb, GA
State Route 14100
Peachtree Indtrl Blvd at I-285
151,600
3,048
Atlanta
Fulton, GA
Interstate 20
I-20 at Fulton St
199,000
3,876
Atlanta
Fulton, GA
State Route 40000
214,400
4,311
Atlanta
Gwinnett, GA
State Route 86400
Near jct. with US-29
59,600
825
(Thous. Hours)
Hawaii
Urban Area
County
Route
Location
Honolulu
Honolulu, HI
Interstate 1
Kalanianaole Hwy-Wailae Ave
Vehicles/Day
171,775
2002 Delay
(Thous. Hours)
2,005
Illinois
80
Vehicles/Day
2002 Delay
Urban Area
County
Route
Location
Chicago-Northwestern IN
Cook, IL
Interstate 90/94
I-90/94 at I-290 Interchange
(“Circle Interchange”)
293,671
25,068
Cook, IL
Interstate 94
I-94 (Dan Ryan Expwy) at I-90
Skyway Split (South)
260,403
16,713
(Thous. Hours)
Cook, IL
Interstate 290
I-290 (Eisenhower Expwy)
Between Exits 17b and 23a
200,441
14,009
Cook, IL
Interstate 55
Pulaski Rd at I-55
188,825
3,162
Cook, IL
Interstate 57
I-57 at 12th St
166,931
1,717
Cook, IL
Interstate 80
I-80/I-94 split (southside)
132,496
2,581
Cook, IL
Interstate 90
I-90 at I-94 Interchange (“Edens
Interchange”)
182,054
2,652
DuPage, IL
Interstate 55
I-55 at I-294 Interchnage
165,903
1,706
DuPage, IL
Interstate 290
I-290 at I-355
213,906
4,301
DuPage, IL
Interstate 355
Roosevelt Rd at I-355
125,095
2,050
Lake, IL
Interstate 294
I-294 at Lake Cook Rd
109,512
2,202
104,537
806
87,166
1,753
Will, IL
Interstate 55
I-55 from Naperville to I-80
(“Crossroads of America”)
Will, IL
Interstate 355
I-355 at I-55
Kentucky
Vehicles/Day
2002 Delay
Urban Area
County
Route
Location
Cincinnati (OH-KY)
Kenton, KY
Interstate 75
167,000
1,775
119,000
1,647
174,287
2,159
(Thous. Hours)
Louisville (KY-IN)
Jefferson, KY
Interstate 64
I-64 at I-65/I-71 Interchange
(“Spaghetti Junction”)
Louisville (KY-IN)
Jefferson, KY
Interstate 264
Urban Area
County
Route
Location
Baton Rouge
East Baton Rouge, LA
Interstate 10
I - 10 at I - 110 Interchange
144,200
725
New Orleans
Orleans, LA
Interstate 10
152,900
3,074
Urban Area
County
Route
Location
Baltimore
Baltimore city, MD
Interstate 95
I - 95 Between I - 895 and SR - 43
189,175
3,168
Baltimore
Baltimore, MD
Interstate 83
152,675
3,070
Baltimore
Baltimore, MD
Interstate 695
219,350
4,411
Baltimore
Baltimore, MD
Interstate 695
I - 695 between I - 70 and I - 95
173,529
2,150
Baltimore
Baltimore, MD
Interstate 795
116,075
1,438
Baltimore
Howard, MD
State Route 100
SR-100 at US-29
66,650
1,319
Montgomery, MD
Interstate 495
I-495 (Capital Beltway) at I-270
243,425
19,492
Prince Georges, MD
Interstate 495
185,125
15,035
Prince Georges, MD
State Route 295
Balt/Wash Pkwyat I - 495/I - 95
Interchange
105,875
881
Prince Georges, MD
State Route 295
Balt/Wash Pkwy at Powder Mill
Rd.
110,675
1,138
Louisiana
Vehicles/Day
2002 Delay
(Thous. Hours)
Maryland
Vehicles/Day
2002 Delay
(Thous. Hours)
81
Massachusetts
Vehicles/Day
2002 Delay
Urban Area
County
Route
Location
Boston
Norfolk, MA
Interstate 93
180,594
2,565
Boston
Norfolk, MA
Interstate 95
Worcester Rd at I-95
166,564
1,713
Boston
Suffolk, MA
Interstate 93
Columbia Rd at I-93
181,560
2,645
Urban Area
County
Route
Location
Detroit
Oakland, MI
Interstate 75
176,896
2,319
Detroit
Oakland, MI
Interstate 696
213,800
1,847
Detroit
Wayne, MI
State Route 39
M-39 at M-5 Interchange
177,000
2,320
Detroit
Wayne, MI
Interstate 75
7 Mile Rd at I-75
172,000
2,069
Detroit
Wayne, MI
Interstate 94
160,289
1,385
Detroit
Wayne, MI
Interstate 96
193,700
1,020
Urban Area
County
Route
Location
Minneapolis-St
Paul
Hennepin, MN
Interstate 94
I-94 at I-35W Interchange
159,000
1,324
Minneapolis-St
Paul
Hennepin, MN
Interstate 35W
I - 35W at SR-62 Interchange
175,603
2,239
Minneapolis-St
Paul
Hennepin, MN
Interstate 394
I - 394 at TH 100 Interchange
150,000
943
Minneapolis-St
Paul
Hennepin, MN
Interstate 494
I - 494 at I-35W Interchange
154,391
1,145
Minneapolis-St
Paul
Ramsey, MN
Interstate 94
I - 94 at I-35E Interchange (“Spaghetti
Bowl”)
160,000
1,382
Urban Area
County
Route
Location
Kansas City (MOKS)
Jackson, MO
Interstate 70
111,874
1,189
St Louis (MO-IL)
St. Louis, MO
Interstate 70
170,360
1,929
Urban Area
County
Route
Location
Omaha (NE-IA)
Douglas, NE
Interstate 80
Urban Area
County
Route
Location
Las Vegas
Clark, NV
US–95
US-95 at I-15 Interchange (“Spaghetti
Bowl”)
190,600
11,152
Las Vegas
Clark, NV
Interstate 15
I-15 at I-215 Interchange (the
“Fishbowl”)
159,670
1,380
Las Vegas
Clark, NV
Interstate 515
I-515 at Eastern Ave
175,300
2,235
(Thous. Hours)
Michigan
Vehicles/Day
2002 Delay
(Thous. Hours)
Minnesota
Vehicles/Day
2002 Delay
(Thous. Hours)
Missouri
Vehicles/Day
2002 Delay
(Thous. Hours)
Nebraska
Vehicles/Day
166,965
2002 Delay
(Thous. Hours)
3,305
Nevada
82
Vehicles/Day
2002 Delay
(Thous. Hours)
New Jersey
Vehicles/Day
2002 Delay
Urban Area
County
Route
Location
New YorkNortheastern NJ
Bergen, NJ
Interstate 80
I-80 at Garden State Pkwy
120,539
1,712
Bergen, NJ
Interstate 95
I-95 at SR-3
292,872
3,734
Essex, NJ
Garden State Pkwy
Garden State Pkwy at I-78
193,161
3,439
Morris, NJ
State Route 24
I-287 at SR-24
98,587
1,982
Ocean, NJ
Garden State Pkwy
SR-549 at Garden State Pkwy
115,274
1,387
Passaic, NJ
Garden State Pkwy
Garden State Pkwy at SR-3
182,647
2,728
Urban Area
County
Route
Location
Albuquerque
Bernalillo, NM
Interstate 25
I - 25 and Paseo Del Norte,
Albuquerque
162,816
1,512
Albuquerque
Bernalillo, NM
Interstate 40
Between I-25 and Paseo Del Norte
150,736
3,031
(Thous. Hours)
New Mexico
Vehicles/Day
2002 Delay
(Thous. Hours)
New York
Vehicles/Day
2002 Delay
Urban Area
County
Route
Location
Albany-Schenectady-Troy
Albany, NY
Interstate 90I
113,085
1,280
Buffalo-Niagara Falls
Erie, NY
Interstate 90I
I-90 at I-290
131,054
2,467
New York-Northeastern NJ
Bronx, NY
Interstate 95I
173,976
2,155
Bronx, NY
Interstate 278I
I-278 (Bruckner Expwy) at I-87
Interchange
117,626
1,542
Kings, NY
Interstate 278I
I-278 (BQE) at I-495 Interchange
201,262
4,047
Nassau, NY
Interstate 495I
I-495 (Long Island Expwy) at Exit
33
203,218
4,086
Nassau, NY
State Route 908G
Northern State Parkway at Exit 36A
112,527
1,235
Nassau, NY
State Route 908M
Southern State Parkway at Exit 25A
196,227
3,694
New York, NY
Interstate 95I
I-95 at SR-9A (Westside Hwy)
298,278
5,998
166,006
1,707
(Thous. Hours)
New York, NY
State Route 907L
FDR Drive south of Triborough
Bridge
Queens, NY
Interstate 278I
I-278 at Exit 36
201,262
4,047
Queens, NY
State Route 495I
I-495 (Long Island Expwy) at
Grand Ave.
222,948
4,483
Queens, NY
Interstate 678I
I-678 at SR-27 Interchange (JFK)
135,062
2,716
Queens, NY
State Route 907M
Grand Central Parkway at Exit 5
172,858
2,079
196,042
3,690
Richmond, NY
Interstate 278I
I-278 (Staten Island Expwy) before
Verrazano Br
Suffolk, NY
State Route 908M
Southern State Parkway at Exit 32
171,806
2,006
Rochester
Monroe, NY
State Route 5900
I-590 at I-490/SR-590 Interchange
(“Can of Worms”)
109,594
1,053
83
North Carolina
Vehicles/Day
2002 Delay
Urban Area
County
Route
Location
Charlotte
Mecklenburg, NC
Interstate 77
I-77 at Tryon Rd
164,000
1,576
Gastonia
Gaston, NC
Interstate 85
I-85 at SR-7
110,000
1,094
(Thous. Hours)
Ohio
Vehicles/Day
2002 Delay
Urban Area
County
Route
Location
Akron
Summit, OH
Interstate 76
I-76 at SR-77 Interchange+J179
117,068
1,492
Akron
Summit, OH
Interstate 77
125,539
2,057
Akron
Summit, OH
Interstate 277
58,428
745
Cincinnati (OH-KY)
Hamilton, OH
Interstate 75
I-75 from Ohio River Bridge to I-71
136,013
10,088
Cincinnati (OH-KY)
Hamilton, OH
US–50
90,274
1,815
Cincinnati (OH-KY)
Hamilton, OH
Interstate 71
I - 71 at I-75 Interchange
133,728
2,647
Cincinnati (OH-KY)
Hamilton, OH
Interstate 75
185,136
2,900
Cincinnati (OH-KY)
Hamilton, OH
Interstate 275
I-275 between I-74 and SR-126
112,851
1,238
Cincinnati (OH-KY)
Hamilton, OH
State Route 562
68,914
1,386
Cleveland
Cuyahoga, OH
Interstate 77
Woodland Ave at I-77
72,083
1,449
Cleveland
Cuyahoga, OH
State Route 176
SR-176 between Snow Rd and
Broadview Rd
63,515
1,086
Cleveland
Cuyahoga, OH
Interstate 271
138,072
1,373
Columbus
Franklin, OH
Interstate 70
157,640
3,170
Columbus
Franklin, OH
Interstate 71
107,722
2,166
Columbus
Franklin, OH
Interstate 270
117,782
1,544
Columbus
Franklin, OH
State Route 315
61,354
939
Dayton
Montgomery, OH
Interstate 75
122,271
1,871
Toledo (OH-MI)
Lucas, OH
Interstate 75
87,016
1,750
Toledo (OH-MI)
Lucas, OH
Interstate 475
I-475 at Monroe St
111,797
2,248
(Thous. Hours)
Oklahoma
Urban Area
County
Route
Location
Vehicles/Day
Tulsa
Tulsa, OK
US–169
Mingo Valley Exwy at S 21st
111,000
2002 Delay
(Thous. Hours)
1,142
Oregon
84
2002 Delay
Urban Area
County
Route
Location
Vehicles/Day
Portland-Vancouver
(OR-WA)
Multnomah, OR
Interstate 5
I-5 Interstate Bridge and bridge
influence area
105,200
843
Portland-Vancouver
(OR-WA)
Multnomah, OR
Interstate 84
177,000
2,320
Portland-Vancouver
(OR-WA)
Multnomah, OR
Interstate 205
I-205 at Powell Blvd
168,100
1,786
Portland-Vancouver
(OR-WA)
Washington, OR
US–26
Sunset Hwy at Murray Blvd
120,200
1,707
Portland-Vancouver
(OR-WA)
Washington, OR
State Route 217
SR-217 at Canyon Rd
121,900
1,820
(Thous. Hours)
Pennsylvania
Vehicles/Day
2002 Delay
Urban Area
County
Route
Location
Chester, PA
US–202
Darby Paoli Rd at US-202
109,377
1,051
Delaware, PA
Interstate 95
147,290
1,931
Montgomery, PA
Interstate 76
I-76 at Walnut La
125,114
2,050
Montgomery, PA
US–202
US-202 at US-422
118,798
1,601
Philadelphia, PA
Interstate 76
I-76 at Girard Av
192,487
3,427
Philadelphia, PA
Interstate 95
I-95 at Chestnut St
168,569
1,850
Pittsburgh
Allegheny, PA
Interstate 376
I-376 at Centreville Rd
111,396
1,184
(Thous. Hours)
Rhode Island
Vehicles/Day
2002 Delay
Urban Area
County
Route
Location
Providence
Providence, RI
Interstate 95
256,000
15,340
Providence
Kent, RI
Interstate 95
I-95 at Route 4 Interchange
173,700
719
Urban Area
County
Route
Location
Chattanooga (TNGA)
Hamilton, TN
Interstate 24
I-24 at I-440N Interchange
113,250
1,282
Nashville
Davidson, TN
Interstate 24
Harding Pl at I-24
132,930
2,589
Nashville
Davidson, TN
Interstate 40
141,520
2,846
Nashville
Davidson, TN
Interstate 440
I-440S at US-431
111,010
1,142
(Thous. Hours)
Tennessee
Vehicles/Day
2002 Delay
(Thous. Hours)
Texas
Vehicles/Day
2002 Delay
Urban Area
County
Route
Location
Austin
Travis, TX
Interstate 35
I-35 at Martin Luther King Jr
217,372
4,371
Austin
Travis, TX
State Route 1
MOPAC Expy-Capital of Texas
124,570
1,996
Dallas-Fort Worth
Collin, TX
US–75
US-75 to SR-190 F
234,791
3,078
Dallas-Fort Worth
Dallas, TX
Interstate 35E
I - 35E at I - 30 interchange (“Mixmaster”)
182,094
2,719
Dallas-Fort Worth
Dallas, TX
Interstate 635
I-635 at N. Dallas Tollway
259,930
4,806
Dallas-Fort Worth
Dallas, TX
State Route 183
SR-183 at International Pkwy
164,770
1,639
Dallas-Fort Worth
Dallas, TX
US–75
US-75 at Lemmon Av
186,379
2,987
Dallas-Fort Worth
Tarrant, TX
Interstate 35W
I - 35W at SH - 121 Interchange
102,159
728
Dallas-Fort Worth
Tarrant, TX
Interstate 820
SR-121 at I-820
153,691
3,090
Dallas-Fort Worth
Tarrant, TX
State Route 121
Central at SR-121
189,380
3,808
Dallas-Fort Worth
Tarrant, TX
State Route 360
SR-183 at SR-360
144,822
2,912
El Paso (TX-NM)
El Paso, TX
Interstate 10
I-10 at I-110/US-54 Interchange
200,680
2,414
Houston
Harris, TX
Interstate 45
250,299
13,944
Houston
Harris, TX
Interstate 610
295,000
25,181
Houston
Fort Bend, TX
US–59
147,668
2,969
Houston
Harris, TX
Interstate 45
266,990
5,368
(Thous. Hours)
85
Houston
Harris, TX
State Route 146
SR-146 at La Porte Frwy
65,560
1,234
Houston
Harris, TX
State Route 288
SR-288 at US-59
157,551
3,168
Houston
Harris, TX
US–290
Spencer Rd at US-290
237,676
4,779
San Antonio
Bexar, TX
Interstate 10
I-10 at I-410 Loop North Interchange
158,400
3,185
San Antonio
Bexar, TX
Interstate 35
I - 35 at Loop 410 Interchange
160,461
1,386
San Antonio
Bexar, TX
Interstate 410
Loop 410 at US - 281 interchange
167,325
1,778
Utah
Vehicles/Day
2002 Delay
Urban Area
County
Route
Location
Salt Lake City
Davis, UT
Interstate 15
179,510
2,484
Salt Lake City
Salt Lake, UT
Interstate 15
194,661
3,533
Urban Area
County
Route
Location
Norfolk Virginia
Beach-Newport
News
Chesapeake, VA
Interstate 664
124,874
2,046
Richmond
Chesterfield, VA
State Route 150
US-1 at Chippenham Pkwy
53,713
1,080
Richmond
Richmond, VA
Interstate 64
97,358
1,958
Richmond
Richmond, VA
Interstate 195
88,636
1,194
Arlington, VA
Interstate 66
I-66 at US-29 Interchange (E. Falls
Church)
113,696
1,287
Arlington, VA
US–50
Arlington Blvd-Washington Blvd
60,711
907
Fairfax, VA
Interstate 66
Centreville Rd at I-66
188,115
3,082
Fairfax, VA
Interstate 66
I-66 at I-495 (Capitol Beltway)
Interchange
180,922
2,048
Fairfax, VA
Interstate 495
I-95 - Woodrow Wilson Bridge
197,112
2,163
Norfolk, VA
Interstate 64
143,768
1,730
Norfolk, VA
Interstate 264
I-264 at Downtown Tunnel
113,690
1,287
Urban Area
County
Route
Location
Bremerton
Kitsap, WA
State Route 16
SR-16 at SR-3
Seattle
King, WA
Interstate 5
Seattle
King, WA
Seattle
(Thous. Hours)
Virginia
Vehicles/Day
2002 Delay
(Thous. Hours)
Washington
Vehicles/Day
2002 Delay
(Thous. Hours)
63,263
1,082
301,112
14,306
Interstate 405
I-405 in Downtown Bellevue
200,590
1,262
King, WA
State Route 520
SR-520 Floating Bridge
100,280
804
Seattle
Pierce, WA
State Route 16
SR-16 at Sprague Av
116,428
1,484
Seattle
Snohomish, WA
Interstate 5
I-5 NB at SR 526 in Everett
147,095
848
Urban Area
County
Route
Location
Appleton-Neenah
Winnebago, WI
US–10E
US-10 at US-441 Interchange
Milwaukee
Milwaukee, WI
Interstate 94
US–45N
Wisconsin
Milwaukee
86
Milwaukee, WI
Vehicles/Day
2002 Delay
(Thous. Hours)
59,426
801
I-94 W. of Marquette Interchange
155,374
1,152
US-45 at I-94/I-894 Interchange (the
“Zoo”)
143,108
2,878
APPENDIX C: Major Bottlenecks Ranked 1 to 233
APPENDIX C; Major Bottlenecks Ranked 1 to 234
Rank
Urban Area
County
Route
Location
Vehicles/Day
2002 Delay
318,000
27,144
(Thous Hrs)
1
Los Angeles
Los Angeles, CA
US–101
US-101 (Ventura Fwy) at
I-405 Interchange
2
Houston
Harris, TX
Interstate 610
(West)
295,000
25,181
3
ChicagoNorthwestern IN
Cook, IL
Interstate 90/94
I-90/94 at I-290 Interchange
(“Circle Interchange”)
293,671
25,068
4
Phoenix
Maricopa, AZ
Interstate 10
I-10 at SR-51/SR-202
Interchange (“Mini-Stack”)
280,800
22,805
5
Los Angeles
Los Angeles, CA
Interstate 405
I-405 (San Diego Fwy) at
I-10 Interchange
296,000
22,792
6
Atlanta
Fulton, GA
Interstate 75
259,128
21,045
7
Montgomery, MD
Interstate 495
I-495 (Capital Beltway) at
I-270
243,425
19,492
8
Los Angeles
Los Angeles, CA
Interstate 10
I-10 (Santa Monica Fwy) at
I-5 Interchange
318,500
18,606
9
Los Angeles
Orange, CA
Interstate 405
I-405 (San Diego Fwy) at
I-605 Interchange
318,000
18,606
10
Atlanta
DeKalb, Ga
Interstate 285
266,000
17,072
11
Cook, IL
Interstate 94
I-94 (Dan Ryan Expwy) at
I-90 Skyway Split (South)
260,403
16,713
12
Phoenix
Maricopa, IL
Interstate 17
I-17 (Black Canyon Fwy)
between I-10 and Cactus Rd.
208,000
16,310
13
Los Angeles
Orange, CA
Interstate 5
I-5 (Santa Anna Fwy) at SR22/57 Interchange (“Orange
Crush”)
308,000
16,304
14
Providence
Providence, RI
Interstate 95
256,000
15,340
15
Prince Georges, MD
Interstate 495
I-495 at I- 95 Interchange
185,125
15,035
16
Tampa
Hillsborough, FL
Interstate 275
(“Malfunction Junction”)
201,500
14,371
17
Atlanta
Cobb, GA
Interstate 285
I-285 at I-75
239,193
14,333
18
Seattle
King, WA
Interstate 5
301,112
14,306
19
Cook, IL
Interstate 290
I-290 (Eisenhower Expwy)
between Exits 17b and 23a
200,411
14,009
20
Houston
Harris, TX
Interstate 45
I-45 (Gulf Freeway) at US-59
Interchange
250,299
13,944
21
San Jose
Santa Clara, CA
US–101
US-101 at 1-880 Interchange
244,000
12,249
22
Las Vegas
Clark, NV
US–95
(“Spaghetti Bowl”)
190,600
11,152
23
San Diego
San Diego, CA
Interstate 805
238,000
10,992
24
Cincinnati (OH-KY)
Hamilton, OH
Interstate 75
I-75 from Ohio River Bridge
to I-71
136,013
10,088
25
Los Angeles
Orange, CA
Interstate 5
I-5 (San Diego Fwy) at I-405
Interchange (“El Toro”)
356,000
6,460
26
New York, NY
Interstate 95I
I-95 at SR-9A (Westside
Hwy)
298,278
5,998
27
Miami-Hialeah
Broward, FL
Interstate 95
296,000
5,952
28
Los Angeles
Los Angeles, CA
Interstate 110
I-110 at Saulson Ave
320,000
5,585
29
Alameda, CA
Interstate 880
I-880 at I-238
271,000
5,449
30
Houston
Harris, TX
Interstate 45
266,990
5,368
87
Rank
88
Urban Area
County
Route
Location
Vehicles/Day
2002 Delay
(Thous Hrs)
31
Dallas-Fort Worth
Dallas, TX
Interstate 635
I-635 at N. Dallas Tollway
259,930
4,806
32
Denver
Adams, CO
Interstate 25
US-87 at US-36
237,839
4,782
33
Houston
Harris, TX
US–290
Spencer Rd at US-290
237,676
4,779
34
Alameda, CA
Interstate 80
I-80 at Central St
259,000
4,700
35
Los Angeles
San Bernardino, CA
Interstate 10
San Bernardino Frwy
258,000
4,682
36
Los Angeles
Orange, CA
State Route 91
Orange Frwy
234,000
4,632
37
Queens, NY
State Route 495I
I-495 (Long Island Expwy)
at Grand Ave.
222,948
4,483
38
Baltimore
Baltimore, MD
Interstate 695
219,350
4,411
39
Austin
Travis, TX
Interstate 35
I-35 at Martin Luther King Jr
217,372
4,371
40
San Mateo, CA
US–101
253,000
4,326
41
Atlanta
Fulton, GA
State Route 40000
214,400
4,311
42
DuPage, IL
Interstate 290
I-290 at I-355
213,906
4,301
43
San Francisco, CA
US–101
251,000
4,113
44
Nassau, NY
Interstate 495I
I-495 (Long Island Expwy)
at Exit 33
203,218
4,086
45
Kings, NY
Interstate 278I
I-278 (BQE) at I-495
Interchange
201,262
4,047
46
Queens, NY
Interstate 278I
I-278 at Exit 36
201,262
4,047
47
Atlanta
Fulton, GA
Interstate 20
I-20 at Fulton St
199,000
3,876
48
Dallas-Fort Worth
Tarrant, TX
State Route 121
Central at SR-121
189,380
3,808
49
Los Angeles
Los Angeles, CA
State Route 60
I-710 at Whittier Blvd
245,000
3,748
50
Bergen, NJ
Interstate 95
I-95 at SR-3
292,872
3,734
51
Nassau, NY
State Route 908M
Southern State Parkway at
Exit 25A
196,227
3,694
52
Richmond, NY
Interstate 278I
I-278 (Staten Island Expwy)
before Verrazano Br
196,042
3,690
53
Salt Lake City
Salt Lake, UT
Interstate 15
194,661
3,533
54
Essex, NJ
Garden State Pkwy
Garden State Pkwy at I-78
193,161
3,439
55
Philadelphia (PANJ)
Philadelphia, PA
Interstate 76
I-76 at Girard Av
192,487
3,427
56
Jacksonville
Duval, FL
Interstate 95
168,000
3,378
57
Omaha (NE-IA)
Douglas, NE
Interstate 80
166,965
3,305
58
Los Angeles
Los Angeles, CA
State Route 134
238,000
3,293
59
Los Angeles
Los Angeles, CA
State Route 91
San Gabriel River Frwy
283,000
3,204
60
Los Angeles
Los Angeles, CA
Interstate 710
Long Beach Frwy
237,000
3,193
Rank
Urban Area
County
Vehicles/Day
2002 Delay
Route
Location
158,400
3,185
(Thous Hrs)
61
San Antonio
Bexar, TX
Interstate 10
I-10 at I-410 Loop North
Interchange
62
Columbus
Franklin, OH
Interstate 70
157,640
3,170
63
Houston
Harris, TX
State Route 288
SR-288 at US-59
157,551
3,168
64
Baltimore
Baltimore city, MD
Interstate 95
I - 95 between I - 895 and
SR - 43
189,175
3,168
65
Cook, IL
Interstate 55
Pulaski Rd at I-55
188,825
3,162
66
Miami-Hialeah
Broward, FL
State Route 826
154,000
3,097
67
Dallas-Fort Worth
Tarrant, TX
Interstate 820
SR-121 at I-820
153,691
3,090
68
Fairfax, VA
Interstate 66
Centreville Rd at I-66
188,115
3,082
69
Dallas-Fort Worth
Collin, TX
US–75
US-75 to SR-190 F
234,791
3,078
70
New Orleans
Orleans, LA
Interstate 10
152,900
3,074
71
Baltimore
Baltimore, MD
Interstate 83
152,675
3,070
72
Atlanta
De Kalb, GA
State Route 14100
Peachtree Indtrl Blvd at
I-285
151,600
3,048
73
Denver
Denver, CO
Interstate 70
(“Mousetrap”)
151,030
3,037
74
Albuquerque
Bernalillo, NM
Interstate 40
Between I-25 and Paseo Del
Norte
150,736
3,031
75
Dallas-Fort Worth
Dallas, TX
US–75
US-75 at Lemmon Av
186,379
2,987
76
Houston
Fort Bend, TX
US–59
147,668
2,969
77
Los Angeles
Orange, CA
State Route 57
US-57 at US-91
279,000
2,965
78
Dallas-Fort Worth
Tarrant, TX
State Route 360
SR-183 at SR-360
144,822
2,912
79
Miami-Hialeah
Broward, FL
State Route 821
SR-821 near SR-817
144,300
2,901
80
Cincinnati (OH-KY)
Hamilton, OH
Interstate 75
185,136
2,900
143,108
2,878
81
Milwaukee
Milwaukee, WI
US–45N
US-45 at I-94/I-894
Interchange (the “Zoo”)
82
Nashville
Davidson, TN
Interstate 40
141,520
2,846
83
HartfordMiddletown
Hartford, CT
Interstate 84
(“Mixmaster East”)
140,500
2,825
84
Santa Clara, CA
Interstate 880
184,000
2,815
85
Los Angeles
Los Angeles, CA
Interstate 105
230,000
2,767
86
Miami-Hialeah
Broward, FL
State Route 836
SR-836 between I-95 and
I-395
137,500
2,765
87
Orlando
Orange, FL
Interstate 4
(East/West Toll)
183,000
2,733
88
Passaic, NJ
Garden State Pkwy
Garden State Pkwy at SR-3
182,647
2,728
89
Jacksonville
Duval, FL
Interstate 10
I-10 at US-17A Interchange
135,500
2,725
90
Dallas-Fort Worth
Dallas, TX
Interstate 35E
I - 35E at I - 30 Interchange
(“Mixmaster”)
182,094
2,719
89
Rank
90
Urban Area
County
Route
Location
Vehicles/Day
2002 Delay
135,062
2,716
(Thous Hrs)
91
Queens, NY
Interstate 678I
(JFK)
92
Phoenix
Maricopa, AZ
Interstate 10
I-10 at I-17 Interchange West
(the “Stack”)
228,800
2,671
93
Cook, IL
Interstate 90
(“Edens Interchange”)
182,054
2,652
94
Cincinnati (OH-KY)
Hamilton, OH
Interstate 71
I - 71 at I-75 Interchange
133,728
2,647
95
Boston
Suffolk, MA
Interstate 93
Columbia Rd at I-93
181,560
2,645
96
Nashville
Davidson, TN
Interstate 24
Harding Pl at I-24
132,930
2,589
97
Cook, IL
Interstate 80
I-80/I-94 split (southside)
132,496
2,581
98
Boston
Norfolk, MA
Interstate 93
180,594
2,565
99
Salt Lake City
Davis, UT
Interstate 15
179,510
2,484
100
Miami-Hialeah
Broward, FL
Interstate 595
Florida Tpke at I-595
179,500
2,484
101
Miami-Hialeah
Palm Beach, FL
Interstate 95
I-95 at Golden Glades
Interchange
179,500
2,484
102
Atlanta
De Kalb, GA
Interstate 20
179,300
2,481
103
San Diego
San Diego, CA
Interstate 5
225,000
2,469
104
Buffalo-Niagara
Falls
Erie, NY
Interstate 90I
I-90 at I-290
131,054
2,467
105
San Diego
San Diego, CA
Interstate 8
Mission Valley Frwy
248,000
2,467
106
El Paso (TX-NM)
El Paso, TX
Interstate 10
I-10 at I-110/US-54
Interchange
200,680
2,414
107
Los Angeles
Los Angeles, CA
State Route 60
SR-60 at I-605 interchange
223,000
2,370
108
Detroit
Wayne, MI
State Route 39
M-39 at M-5 Interchange
177,000
2,320
109
PortlandVancouver (ORWA)
Multnomah, OR
Interstate 84
177,000
2,320
110
Detroit
Oakland, MI
Interstate 75
176,896
2,319
111
San Mateo, CA
Interstate 280
221,000
2,273
112
Toledo (OH-MI)
Lucas, OH
Interstate 475
I-475 at Monroe St
111,797
2,248
113
Minneapolis-St
Paul
Hennepin, MN
Interstate 35W
I - 35W at SR-62 Interchange
175,603
2,239
114
Las Vegas
Clark, NV
Interstate 515
I-515 at Eastern Ave
175,300
2,235
115
Lake, IL
Interstate 294
I-294 at Lake Cook Rd
109,512
2,202
116
Riverside-San
Bernardino
Riverside, CA
State Route 91
264,000
2,198
117
Columbus
Franklin, OH
Interstate 71
107,722
2,166
118
Fairfax, VA
Interstate 495
I-95 - Woodrow Wilson
Bridge
197,112
2,163
119
Louisville (KY-IN)
Jefferson, KY
Interstate 264
174,287
2,159
120
Bronx, NY
Interstate 95I
173,976
2,155
Rank
Urban Area
County
Route
Location
Vehicles/Day
2002 Delay
173,529
2,150
(Thous Hrs)
121
Baltimore
Baltimore, MD
Interstate 695
I - 695 between I - 70 and
I - 95
122
Phoenix
Maricopa, AZ
State Route 202
Loop-202: Dobson to I - 10
218,400
2,099
123
San Francisco, CA
State Route 80
SR80 at US-101 Interchange
218,000
2,096
124
Queens, NY
State Route 907M
Grand Central Parkway at
Exit 5
172,858
2,079
125
Sacramento
Sacramento, CA
State Route 99
SR-99 at Stockton Blvd
172,000
2,069
126
Detroit
Wayne, MI
Interstate 75
7 Mile Rd at I-75
172,000
2,069
127
Akron
Summit, OH
Interstate 77
125,539
2,057
128
Philadelphia (PANJ)
Montgomery, PA
Interstate 76
I-76 at Walnut La
125,114
2,050
129
DuPage, IL
Interstate 355
Roosevelt Rd at I-355
125,095
2,050
130
Fairfax, VA
Interstate 66
I-66 at I-495 (Capitol
Beltway) Interchange
180,922
2,048
131
NorfolkVirginia
Beach-Newport
News
Chesapeake, VA
Interstate 664
124,874
2,046
132
Suffolk, NY
State Route 908M
Southern State Parkway at
Exit 32
171,806
2,006
133
Honolulu
Honolulu, HI
Interstate 1
Kalanianaole Hwy-Wailae
Ave
171,775
2,005
134
Austin
Travis, TX
State Route 1
MOPAC Expy-Capital of
Texas
124,570
1,996
135
Antioch-Pittsburgh
Contra Costa, CA
State Route 4
SR-4 at Willow Pass Rd
124,000
1,987
136
Morris, NJ
State Route 24
I-287 at SR-24
98,587
1,982
137
Richmond
Richmond, VA
Interstate 64
97,358
1,958
138
Philadelphia (PANJ)
Delaware, PA
Interstate 95
147,290
1,931
139
St Louis (MO-IL)
St. Louis, MO
Interstate 70
170,360
1,929
140
Contra Costa, CA
Interstate 680
I-680 at US-13
170,000
1,925
141
Interstate 95
I-95 at Mt. Vernon Memorial
170,000
1,925
142
Dayton
Montgomery, OH
Interstate 75
122,271
1,871
143
Philadelphia (PANJ)
Philadelphia, PA
Interstate 95
I-95 at Chestnut St
168,569
1,850
144
Detroit
Oakland, MI
Interstate 696
213,800
1,847
145
Washington, OR
State Route 217
SR-217 at Canyon Rd
121,900
1,820
146
Cincinnati (OH-KY)
Hamilton, OH
US–50
90,274
1,815
147
Multnomah, OR
Interstate 205
I-205 at Powell Blvd
168,100
1,786
148
Riverside-San
Bernardino
Riverside, CA
Interstate 215
Pomona Frwy at SR-91
Interchange
168,000
1,785
149
San Antonio
Bexar, TX
Interstate 410
Loop 410 at US - 281
interchange
167,325
1,778
150
Cincinnati (OH-KY)
Kenton, KY
Interstate 75
167,000
1,775
91
Rank
92
Urban Area
County
Route
Location
Vehicles/Day
2002 Delay
(Thous Hrs)
151
Will, IL
Interstate 355
I-355 at I-55
87,166
1,753
152
Toledo (OH-MI)
Lucas, OH
Interstate 75
87,016
1,750
153
Norfolk, VA
Interstate 64
143,768
1,730
154
Cook, IL
Interstate 57
I-57 at 12th St
166,931
1,717
155
Boston
Norfolk, MA
Interstate 95
Worcester Rd at I-95
166,564
1,713
156
Bergen, NJ
Interstate 80
I-80 at Garden State Pkwy
120,539
1,712
157
Phoenix
Maricopa, AZ
US–60
US-60 (Superstition Fwy) at
Loop-101 to I - 10
166,400
1,711
158
New York, NY
State Route 907L
FDR Drive south of
Triborough Bridge
166,006
1,707
159
Washington, OR
US–26
Sunset Hwy at Murray Blvd
120,200
1,707
160
DuPage, IL
Interstate 55
I-55 at I-294 Interchnage
165,903
1,706
161
Miami-Hialeah
Broward, FL
State Route 112
(MP 0.000)
95,735
1,671
162
Alameda, CA
Interstate 238
I-238 at I-550
119,000
1,647
163
Louisville (KY-IN)
Jefferson, KY
Interstate 64
I-64 at I-65/I-71 Interchange
119,000
1,647
164
Dallas-Fort Worth
Dallas, TX
State Route 183
SR-183 at International
Pkwy
164,770
1,639
165
Philadelphia (PANJ)
Montgomery, PA
US–202
US-202 at US-422
118,798
1,601
166
Miami-Hialeah
Broward, FL
US–441
US-441 near SR-383
78,500
1,578
167
Charlotte
Mecklenburg, NC
Interstate 77
I-77 at Tryon Rd
164,000
1,576
168
Columbus
Franklin, OH
Interstate 270
(West)
117,782
1,544
169
Bronx, NY
Interstate 278I
I-278 (Bruckner Expwy) at
I-87 Interchange
117,626
1,542
170
New Haven(064)Meriden (212)
New Haven, CT
Interstate 91
93,900
1,539
171
Albuquerque
Bernalillo, NM
Interstate 25
I - 25 and Paseo Del Norte,
Albuquerque
162,816
1,512
172
Akron
Summit, OH
Interstate 76
I-76 at SR-77
Interchange+J179
117,068
1,492
173
Seattle
Pierce, WA
State Route 16
SR-16 at Sprague Av
116,428
1,484
174
New Haven, CT
Interstate 95
139,600
1,484
175
Cleveland
Cuyahoga, OH
Interstate 77
Woodland Av at I-77
72,083
1,449
176
Baltimore
Baltimore, MD
Interstate 795
116,075
1,438
177
Ocean, NJ
Garden State Pkwy
SR-549 at Garden State
Pkwy
115,274
1,387
178
San Antonio
Bexar, TX
Interstate 35
I - 35 at Loop 410
Interchange
160,461
1,386
179
Cincinnati (OH-KY)
Hamilton, OH
State Route 562
68,914
1,386
180
Detroit
Wayne, MI
Interstate 94
160,289
1,385
Rank
Urban Area
County
Route
Location
Vehicles/Day
2002 Delay
(Thous Hrs)
181
Minneapolis-St
Paul
Ramsey, MN
Interstate 94
I - 94 at I-35E Interchange
(“Spaghetti Bowl”)
160,000
1,382
182
Las Vegas
Clark, NV
Interstate 15
I-15 at I-215 Interchange (the
“Fishbowl”)
159,670
1,380
183
Cleveland
Cuyahoga, OH
Interstate 271
138,072
1,373
184
San Diego
San Diego, CA
Interstate 15
(Escondido)
202,000
1,325
185
Minneapolis-St
Paul
Hennepin, MN
Interstate 94
I-94 at I-35W Interchange
159,000
1,324
186
Baltimore
Howard, MD
State Route 100
SR-100 at US-29
66,650
1,319
187
Arlington, VA
Interstate 66
I-66 at US-29 Interchange (E.
Falls Church)
113,696
1,287
188
Norfolk, VA
Interstate 264
I-264 at Downtown Tunnel
113,690
1,287
189
Chattanooga (TNGA)
Hamilton, TN
Interstate 24
I-24 at I-440N Interchange
113,250
1,282
190
AlbanySchenectady-Troy
Albany, NY
Interstate 90I
113,085
1,280
191
Seattle
King, WA
Interstate 405
I-405 in Downtown Bellevue
200,590
1,262
192
Philadelphia (PANJ)
New Castle, DE
Interstate 95
199,677
1,256
193
Cincinnati (OH-KY)
Hamilton, OH
Interstate 275
I-275 Between I-74 and
SR-126
112,851
1,238
194
Nassau, NY
State Route 908G
Northern State Parkway at
Exit 36A
112,527
1,235
195
Houston
Harris, TX
State Route 146
SR-146 at La Porte Frwy
65,560
1,234
112,320
1,232
196
Phoenix
Maricopa, AZ
State Route 101
Loop-101 Agua Fria at 67th
Ave to I - 17
197
Denver
Arapahoe, CO
Interstate 225
112,202
1,231
198
Denver
Denver, CO
Interstate 225
112,202
1,231
199
Richmond
Richmond, VA
Interstate 195
88,636
1,194
200
Kansas City (MOKS)
Jackson, MO
Interstate 70
111,874
1,189
201
Miami-Hialeah
Broward, FL
State Route 874
SR-874 near SR-821
111,500
1,185
202
Pittsburgh
Allegheny, PA
Interstate 376
I-376 at Centreville Rd
111,396
1,184
203
Milwaukee
Milwaukee, WI
Interstate 94
I-94 W. of Marquette
Interchange
155,374
1,152
204
Minneapolis-St
Paul
Hennepin, MN
Interstate 494
I - 494 at I-35W Interchange
154,391
1,145
205
Interstate 695
I-695 at S. Capitol St
111,030
1,142
206
Nashville
Davidson, TN
Interstate 440
I-440S at US-431
111,010
1,142
207
Tulsa
Tulsa, OK
US–169
Mingo Valley Exwy at S 21st
111,000
1,142
208
Prince Georges, MD
State Route 295
Balt/Wash Pkwy at Powder
Mill Rd.
110,675
1,138
209
Santa Cruz
Santa Cruz, CA
State Route 1
110,000
1,094
210
Gastonia
Gaston, NC
Interstate 85
I-85 at SR-7
110,000
1,094
93
Rank
94
Urban Area
County
Route
Location
Vehicles/Day
2002 Delay
(Thous Hrs)
211
Cleveland
Cuyahoga, OH
State Route 176
SR-176 between Snow Rd
and Broadview Rd
63,515
1,086
212
Bremerton
Kitsap, WA
State Route 16
SR-16 at SR-3
63,263
1,082
213
Richmond
Chesterfield, VA
State Route 150
US-1 at Chippenham Pkwy
53,713
1,080
214
Rochester
Monroe, NY
State Route 5900
I-590 at I-490/SR-590
Interchange (“Can of
Worms”)
109,594
1,053
215
Orlando
Osceola, FL
Interstate 4
US-192 at I-4
109,423
1,052
216
Philadelphia (PANJ)
Chester, PA
US–202
Darby Paoli Rd at US-202
109,377
1,051
217
Detroit
Wayne, MI
Interstate 96
193,700
1,020
218
Minneapolis-St
Paul
Hennepin, MN
Interstate 394
I - 394 at TH 100 Interchange
150,000
943
219
Columbus
Franklin, OH
State Route 315
61,354
939
220
Arlington, VA
US–50
Arlington Blvd-Washington
Blvd
60,711
907
221
Alameda, CA
Interstate 580
I-580 MP 17-19
189,000
906
222
Prince Georges, MD
State Route 295
Balt/Wash Pkwy at I - 495/I
- 95 Interchange
105,875
881
223
Seattle
Snohomish, WA
Interstate 5
I-5 NB at SR 526 in Everett
147,095
848
224
Multnomah, OR
Interstate 5
I - 5 Interstate Bridge and
bridge influence area
105,200
843
225
Atlanta
Gwinnett, GA
State Route 86400
Near jct. with US-29
59,600
825
226
Fairfield, CT
Interstate 95
146,300
806
227
Will, IL
Interstate 55
I-55 from Naperville to I-80
(“Crossroads of America”)
104,537
806
228
Seattle
King, WA
State Route 520
SR-520 Floating Bridge
100,280
804
229
Appleton-Neenah
Winnebago, WI
US–10E
US-10 at US-441 Interchange
59,426
801
230
Akron
Summit, OH
Interstate 277
58,428
745
231
Dallas-Fort Worth
Tarrant, TX
Interstate 35W
I - 35W at SH - 121
Interchange
102,159
728
232
Baton Rouge
East Baton Rouge, LA
Interstate 10
I - 10 at I - 110 Interchange
144,200
725
233
Providence
Kent, RI
Interstate 95
I-95 at Route 4 Interchange
173,700
719
American Highway Users Alliance
One Thomas Circle, NW
10th Floor
Washington, DC 20005
www.highways.org

Unclogging America`s Arteries - American Highway Users Alliance

Transcription

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