Tolou Esfandeh, Masoumeh Taslimi, Rajan Batta, Changhyun Kwon.

Transcription

Tolou Esfandeh, Masoumeh Taslimi, Rajan Batta, Changhyun Kwon.
Impact of Dual-Toll Pricing in Hazmat Transportation considering
Stochastic Driver Preferences
Tolou Esfandeh, Masoumeh Taslimi, Rajan Batta, Changhyun Kwon.
Department of Industrial & Systems Engineering, University at Buffalo, SUNY, Buffalo, NY 14260, USA,
Dual Toll Pricing Problem-Basic Model
Hazardous Material (Hazmat)
Solution Algorithm- Multiple Toll case
β–Ί We assume there are multiple tollable links in the network.
β–Ί Problem (P) represents the basic formulation of the dual toll pricing model.
Cyclic Algorithm
β–Ί The objective function for (P) is to minimize the overall risk consequence in the network, which is the aggregated risk
β–Ί For each tollable link 𝑙, π‘˜ , we are interested in finding a regular toll
consequence on each arc (i, j).
P
min
πœƒ,πœ‡
πœƒπ‘™π‘˜ and a hazmat toll πœ‡π‘™π‘˜ .
𝑅𝑖𝑗 (π‘₯𝑖𝑗 , 𝑦𝑖𝑗 )
𝑖,𝑗 ∈𝐴
Subject to:
β–Ί The set of decision variables is ordered as
π‘₯𝑖𝑗 =
𝛿𝑖𝑗 β„Žπ‘
𝑝
βˆ€ 𝑖, 𝑗 ∈ 𝐴,
𝑝
βˆ€ 𝑖, 𝑗 ∈ 𝐴,
πœ‰ = πœ‡1 , πœƒ1 , πœ‡2 , πœƒ2 , … ,
π‘βˆˆπ‘ƒ
𝑦𝑖𝑗 =
𝛿𝑖𝑗 𝑓𝑝
β–Ί We propose a heuristic algorithm for solving the dual toll pricing
π‘βˆˆπ‘„
𝑝
β„Žπ‘ = π‘‘π‘Ÿπ‘  πœ™π‘Ÿπ‘ 
𝑝
𝑓𝑝 = π‘’π‘Ÿπ‘  πœ“π‘Ÿπ‘ 
Source: U.S. Department of Transportation
𝛼𝑝
𝛽𝑝
βˆ€π‘ ∈ π‘ƒπ‘Ÿπ‘  ,
βˆ€π‘ ∈ π‘„π‘Ÿπ‘ 
𝑝
𝛼𝑝 =
𝛿𝑖𝑗 πœƒπ‘–π‘—
model with stochastic drivers' preferences for the case of multiple
π‘Ÿ, 𝑠 ∈ π‘Š,
π‘Ÿ, 𝑠 ∈ 𝑍.
regular or hazmat tolls.
βˆ€ 𝑝 ∈ 𝑃,
β–Ί A cyclic algorithm, which aims to sequentially solve single toll
𝑖,𝑗 ∈𝐴
Motivation
𝑝
𝛽𝑝 =
𝛿𝑖𝑗 πœ‡π‘–π‘—
βˆ€ 𝑝 ∈ 𝑄,
problems, is proposed.
𝑖,𝑗 ∈𝐴
Hazmat accidents :
β€’ Rarely happen (low-probability incidents), but
β€’ If they do occur, the consequences can be disastrous (high-consequence incidents),.
β€’ In each iteration either a regular toll or a hazmat toll is being
πœƒ π‘šπ‘–π‘› ≀ πœƒπ‘–π‘—
≀ πœƒ π‘šπ‘Žπ‘₯
βˆ€ 𝑖, 𝑗 ∈ 𝐴,
πœ‡π‘šπ‘–π‘› ≀ πœ‡π‘–π‘—
≀ πœ‡π‘šπ‘Žπ‘₯
βˆ€ 𝑖, 𝑗 ∈ 𝐴,
optimized while the other tolls set to their most updated values.
β€’ In every two iterations of the above algorithm, we set the
β–Ί Where πœƒπ‘–π‘— and πœ‡π‘–π‘— are regular and hazmat toll associated with arc 𝑖, 𝑗 .
Who/ What is at risk?
πœ‡ 𝐴 ,πœƒπ΄
optimal values of the regular and hazmat tolls of a certain link
β–Ί Environment
and then continue with the next link
Measuring Hazmat Accident Risk
β–Ί Hazmat carriers. Ex. truck drivers, personnel
β–Ί Regular vehicle drivers, passengers
β–Ί People residing in the vicinity of the roads and highways
Case Study: Sioux Falls Road network
β–Ί Consider the following notation used for risk measurement:
β€˜β€™Therefore, it is important to make risk-averse route decisions in hazmat transportation’’ to:
1. To explore computational efficiency and convergence of the algorithm:
o Separate the hazmat flow from the normal traffic flow.
β€’ We ran Cyclic Algorithm for the Sioux Falls network for different combinations of network
o Route hazmat flow in the less populated areas.
characteristics (i.e., number of OD pairs, number of the k shortest paths, number of the p dissimilar
paths and number of tollable links for regular vehicles and hazmat trucks).
β–Ί The risk measurement function computes both direct consequence and indirect consequence of a hazmat accident.
2
π‘Ÿ
𝑅𝑖𝑗 π‘₯𝑖𝑗 , 𝑦𝑖𝑗 = πœ”1 π‘₯𝑖𝑗
𝑦𝑖𝑗 𝑑𝑖𝑗 + πœ”2 𝑦𝑖𝑗 πœŒπ‘–π‘— 𝐴𝑖𝑗 πœ‹π‘–π‘—
Hazmat Incident Summary by Transportation Phase for 2012
How to Control Network Flows?
β–Ί Network Design Approach
Damage to the population in the vicinity of the
accident
(Indirect consequence)
Damage to regular vehicles
(Direct consequence)
β€’
To compute 𝐴𝑖𝑗 , we use the πœ† βˆ’neighborhood method where πœ† represents the radius of spread for the hazmat.
π‘Ÿ
β€’ πœ‹π‘–π‘—
, the probability of hazmat accidents, is usually in the range of 10βˆ’7 to 10βˆ’6 per mile traveled.
2. To study the impact of the dual toll pricing versus single toll pricing:
β€’ By Single Toll Pricing, we mean only hazmat toll pricing.
β€’ The weight factors πœ”1 and πœ”2 are conversion factors making the two terms of the same unit and the same order of
β–Ί Toll System Approach
β€’ Close/ Open road segments
β€’ Charge tolls to vehicles traveling certain road segments
β€’ Increase capacity of road segments
β€’ Single toll/ Dual toll pricing is possible.
Research Objectives
β€’ The regular drivers take the shortest path toward their destination.
magnitude.
β€’
Probability of Selecting a Path
𝑝
We consider 150 OD pairs for regular vehicles and 10 OD pairs for hazmat, 20 shortest
paths and 15 dissimilar paths, while varying the number of tollable links to 1, 2, 4 and 8.
𝑝
β–Ί In problem (P) , we need to replace πœ™π‘Ÿπ‘  (𝛼𝑝 ) and πœ“π‘Ÿπ‘  (𝛽𝑝 ) with equivalent formulas.
𝑝
β–Ί Consider πœ™π‘Ÿπ‘  (𝛼𝑝 ) for regular vehicle case:
β–Ί To apply Dual -Toll Setting approach in regulating hazmat transportation, in order to:
β–Ί We assume 𝛾 ∈ π‘ˆπ‘›π‘–π‘“π‘œπ‘Ÿπ‘š π‘Žπ›Ύ , 𝑏𝛾 ,
β€’ Route both hazmat and regular carriers
𝑝
β€’ Minimize the total hazmat transport risk
πœ™π‘Ÿπ‘  𝛼𝑝 = Pr 𝑐𝑝 = min
𝑐𝑝′
β€²
βˆ€ π‘Ÿ, 𝑠
𝑝 βˆˆπ‘ƒπ‘Ÿπ‘ 
= Pr 𝛾 πœπ‘ βˆ’ πœπ‘β€² ≀ 𝛼𝑝′ βˆ’ 𝛼𝑝
β–Ί To consider Stochastic Driver Preferences in route selection based on toll prices and travel time,
βˆ€π‘β€² ∈ π‘ƒπ‘Ÿπ‘  βˆ– 𝑝
∈ π‘Š,
βˆ€π‘ ∈ π‘ƒπ‘Ÿπ‘ 
βˆ€ π‘Ÿ, 𝑠 ∈ π‘Š.
β–Ί This inequality depends on the sign of coefficient πœπ‘ βˆ’ πœπ‘β€² .
Sioux Falls Network
Alternative Approach
Stochastic Drivers’ Preferences
1) The joint interval for those pβ€² paths with positive 𝝉𝒑 βˆ’ 𝝉𝒑′ coefficient is the β€œminimum’’ of the intervals:
𝑝
π‘’π‘Ÿπ‘  𝛼 =
β–Ί Generally, there are two main sources of uncertainty in drivers’ route choices:
1. Error component in the perceived travel time,
usually modeled as an additive stochasticity,
2. Uncertain distribution of value of Time (VoT)
modeled as a multiplicative stochasticity.
Inclusion of Stochastic Drivers’ Preferences
𝑝′ : 𝜏 𝑝 βˆ’πœπ‘β€² >0
𝛼𝑝′ βˆ’ 𝛼𝑝
πœπ‘ βˆ’ πœπ‘β€²
β€’ This equation first finds the intersections of linear functions of the form
𝑝
π‘£π‘Ÿπ‘  𝛼 =
mπ‘Žπ‘₯
β–Ί We assume flow-independent path travel time.
3)
Total traveling cost along path p
assigned for the path p for hazmat trucks.
Dual Toll Pricing
𝑝′ : 𝜏 𝑝 βˆ’πœπ‘β€² <0
Single Toll Pricing
β€’ Both single and dual toll show a non-increasing behavior of the risk value,
𝛼𝑝′ βˆ’π›Όπ‘
πœπ‘ βˆ’πœπ‘β€²
. Then, in each interval between
Consequently, the distance in the interval π‘Žπ›Ύ , 𝑏𝛾 in which path p has the smallest travel cost among all other paths in an
β€’ For every point of the two graphs the risk of network in the dual toll
case is less than the single toll case.
O-D pair is the shared distance between two β€œmin” and β€œmax” operators.
𝑝
𝑝
𝑒
𝛼
βˆ’
𝑣
𝑝
π‘Ÿπ‘ 
π‘Ÿπ‘  (𝛼)
πœ™π‘Ÿπ‘  𝛼 =
𝑏𝛾 βˆ’ π‘Žπ›Ύ
Total travel time for the path p
β–Ί The same approach can be applied for hazmat trucks where πœ† denotes the stochastic VoT, and 𝛽𝑝 is the toll
. Then, in each interval between
two intersections, the β€œmax” operator finds the line with the largest value.
β–Ί We define the deterministic part as the total toll assigned for the path p, and the stochastic part as the
𝑐𝑝 = π›Ύπœπ‘ + 𝛼𝑝
πœπ‘ βˆ’πœπ‘β€²
𝛼𝑝′ βˆ’ 𝛼𝑝
πœπ‘ βˆ’ πœπ‘β€²
β€’ This equation first finds the intersections of linear functions of the form
Total toll assigned for the path p for
regular vehicles
𝛼𝑝′ βˆ’π›Όπ‘
2) The joint interval for those pβ€² paths with n𝐞𝐠𝐚𝐭𝐒𝐯𝐞 𝝉𝒑 βˆ’ 𝝉𝒑′ coefficient is the β€œmaximum’’ of the intervals:
β–Ί A path's travel cost is the sum of two components: one deterministic and the other stochastic.
value of time (VoT) corresponding to path p
Risk value comparison between single and dual toll pricing
two intersections, the β€œmin” operator finds the line with the smallest value.
β–Ί We define a multiplicative stochastic Value of Time to represent the drivers' behavior in route selection.
𝛾 : Stochastic VoT
min
𝑝
π‘’π‘Ÿπ‘ 
Number of Tollable Links
𝑝
π‘£π‘Ÿπ‘ 
β€’ We note that both
and
represent piece-wise linear functions of path toll 𝛼 and consequently link toll πœƒ.
β€’ The special case πœπ‘ βˆ’ πœπ‘β€² =0 is considered in the implementation of the solution algorithm.
𝑝
β€’ The same approach is applied for hazmat trucks in order to calculate πœ“π‘Ÿπ‘  (𝛽𝑝 ) .
Conclusions & Future Research
π‘˜π‘ = πœ†πœπ‘ + 𝛽𝑝
Solution Algorithm-Single Toll case
Flow Distribution Model
𝑝
𝑝
βˆ€ π‘Ÿ, 𝑠
𝑝 βˆˆπ‘ƒπ‘Ÿπ‘ 
= Pr 𝑐𝑝 ≀ 𝑐𝑝′
β€²
βˆ€π‘ ∈ π‘ƒπ‘Ÿπ‘  βˆ– *𝑝+
= Pr 𝛾 πœπ‘ βˆ’ πœπ‘β€² ≀ 𝛼𝑝′ βˆ’ 𝛼𝑝
βˆ€π‘ ∈ π‘ƒπ‘Ÿπ‘ 
βˆ€π‘β€² ∈ π‘ƒπ‘Ÿπ‘  βˆ– 𝑝
βˆ€ π‘Ÿ, 𝑠
link tolls are known constants. Therefore the single decision variable is either πœƒπ‘™π‘˜ or πœ‡π‘™π‘˜ .
βˆˆπ‘Š
βˆ€π‘ ∈ π‘ƒπ‘Ÿπ‘ 
βˆ€ π‘Ÿ, 𝑠 ∈ π‘Š.
β–Ί Where W is the set of all O-D pairs for regular vehicles.
β„Žπ‘ =
𝛼𝑝
βˆ€π‘ ∈ π‘ƒπ‘Ÿπ‘  ,
𝑝
𝛿𝑖𝑗 β„Žπ‘
π‘Ÿ, 𝑠 ∈ π‘Š.
The interval ,πœ‡
β€’
βˆ€ 𝑖, 𝑗 ∈ 𝐴.
π‘šπ‘–π‘›
,πœ‡
π‘šπ‘Žπ‘₯
- is divided into sub-intervals. In each sub-interval, the objective function of problem (P)
is at most linear. Hence, the global optimal solution of a piece-wise linear function can be easily found by
𝑝
β–Ί Applying the same approach for hazmat trucks, the expected hazmat traffic flow along path p is:
π‘Ÿ, 𝑠 ∈ 𝑍.
Proposed Algorithm for Single-Toll variable case
𝛼𝑝′ βˆ’ 𝛼𝑝
πœπ‘ βˆ’ πœπ‘β€²
𝛼𝑝′ βˆ’ 𝛼𝑝
πœπ‘ βˆ’ πœπ‘β€²
𝑝
𝑝
π‘£π‘Ÿπ‘ 
β–Ί Where πœ“π‘Ÿπ‘  𝛽𝑝 is the probability of path p being selected among all paths from origin r to destination s , π‘’π‘Ÿπ‘  is the
O-D hazmat demand, π‘„π‘Ÿπ‘  is the set of all paths in O-D pair (r,s), and Z is the set of all O-D pairs for hazmat trucks.
πœπ‘ βˆ’ πœπ‘β€² < 0
π‘’π‘Ÿπ‘ 
𝑝
𝛿𝑖𝑗 𝑓𝑝
π‘Ÿ,𝑠 βˆˆπ‘ π‘βˆˆπ‘„π‘Ÿπ‘ 
πœπ‘ βˆ’ πœπ‘β€² > 0
𝑝
β–Ί The distributed hazmat traffic flow on arc (𝑖, 𝑗) is :
𝑦𝑖𝑗 =
of value of time; this research assumes uniformly distributed value of time.
β–Ί another extension of the problem is to study dynamic dual toll pricing which
allows the regulator to set dual tolls in a time-sensitive basis.
References
comparing only the extreme points of the sub-intervals.
βˆ€π‘ ∈ π‘„π‘Ÿπ‘ 
β–Ί Another future research opportunity is to consider more general distributions
β–Ί The excess revenue of toll setting can be applied in construction and maintenance of the network.
Case 2: When a hazmat toll, ππ’π’Œ , is the only decision variable and all other link tolls are known constants.
β–Ί Where 𝛿𝑖𝑗 is a binary indicator and is 1 when arc 𝑖, 𝑗 belongs to path p.
𝑝
flow on the path's travel cost function while they distribute in the network.
β–Ί Dual toll pricing not only provides flexible solutions for network regulators but also suggests acceptable
is quadratic. A comparison of the local optimal solution of each sub-interval gives the global optimum.
π‘Ÿ,𝑠 βˆˆπ‘Š π‘βˆˆπ‘ƒπ‘Ÿπ‘ 
𝑓𝑝 = π‘’π‘Ÿπ‘  πœ“π‘Ÿπ‘  𝛽𝑝
associated with toll booths, toll pricing can obviously ensure safer hazmat transportation.
β€’ The interval ,πœƒ π‘šπ‘–π‘› , πœƒ π‘šπ‘Žπ‘₯ - is divided into sub-intervals. In each sub-interval, the objective function of problem (P)
β–Ί Consequently, the expected regular traffic volume on arc (𝑖, 𝑗) is:
π‘₯𝑖𝑗 =
travel times. Thus, one extension is to consider the impact of regular traffic
choices to carriers.
Case 1: When a regular toll, πœ½π’π’Œ , is the only decision variable and all other tolls are known constants.
β–Ί Given the π‘‘π‘Ÿπ‘  , demand of regular vehicles for O-D pair (r, s), the expected regular traffic flow along path p is:
𝑝
π‘‘π‘Ÿπ‘  πœ™π‘Ÿπ‘ 
β–Ί As we impose tolls on more road segments the total risk value decreases. Without considering the cost
β–Ί Setting tolls for both regular and hazmat vehicles is more effective than just hazmat toll pricing.
Single-Toll Variable Case
There is only one link (𝑙, π‘˜) in the network having an unspecified toll for either regular vehicles or hazmat trucks. All other
∈ π‘Š,
β–Ί The current model does not consider congestion and flow dependent link
variable case. Hence, we explore single-toll decision variable case first.
β–Ί The probability of path p being selected when traveling from origin node r to destination node s is:
πœ™π‘Ÿπ‘  𝛼𝑝 = Pr 𝑐𝑝 = min
𝑐𝑝′
β€²
β–Ί Number of OD pairs, dissimilar paths and tollable links in the network greatly impact computational time.
𝑝
β–Ί Replacing πœ™π‘Ÿπ‘  (πœƒ) and πœ“π‘Ÿπ‘  πœ‡ in problem (P), the objective function becomes highly nonlinear for multiple decision
β–Ί A path p is chosen when its associated cost is minimum compared to all other possible paths in O-D pair (r, s).
Risk Value
β–Ί To compare the effect of dual-toll pricing and single-toll pricing in risk mitigation.
βˆ€ 𝑖, 𝑗 ∈ 𝐴.
πœƒ π‘šπ‘–π‘›
πœƒ π‘šπ‘Žπ‘₯
πœƒ π‘šπ‘Žπ‘₯
πœƒ π‘šπ‘–π‘›
β€’ Abkowitz, M., P. Cheng. 1988. Developing a risk/cost framework for routing truck movements of hazardous
materials. Accident Analysis and Prevention 20(1) 39.
β€’ Abkowitz, M., M. Lepofsky, P. Cheng. 1992. Selecting criteria for designating hazardous materials highway
routes. Transportation Research Record 1333 30-35.
β€’ Akiva, M. E. B., S. R. Lerman. 1985. Discrete choice analysis: theory and application to predict travel
demand, vol. 9. The MIT press.
β€’ Alp, E. 1995. Risk-based transportation planning practice: Overall methodology and a case example.
INFORMS 33(1) 4-19.
β€’ Arnott, R., K. Small. 1994. The economics of traffic congestion. American Scientist 82 446-455.
β€’ Bar-Gera, H. 2013. Transportation network test problems. http://www.bgu.ac.il/~bargera/tntp/. Accessed on
May, 2013.
β€’ Batta, R., S. Chiu. 1988. Optimal obnoxious paths on a network: Transportation of hazardous materials.
Operations Research 36(1) 84-92.
β€’ Bianco, L., M. Caramia, S. Giordani, V. Piccialli. 2012. A game theory approach for regulating hazmat
transportation. Tech. rep., Tech. Rep. RR-21.12, Dipartimento di Ingegneria dell'Impresa, University of Rome
β€œTor Vergata", Italy.
β€’ Cantarella, G., M. Binetti. 1998. Stochastic equilibrium traffic assignment with value of time distributed
among users. International Transactions in Operational Research 5.6 541-553.
β€’ Daganzo, C. F., Y. She. 1977. On stochastic models of traffic assignment. Transportation Science 11(3) 253274.
β€’ Dial, R. B. 1996. Bicriterion traffic assignment: basic theory and elementary algorithms. Transportation
Science 30(2) 93-111.
β€’ Dial, R. B. 1999a. Network-optimized road pricing: Part I: A parable and a model. Operations Research
47(1) 54-64.
β€’ Dial, R. B. 1999b. Network-optimized road pricing: Part II: Algorithms and examples. Operations Research
47(2) 327-336.
β€’ Erkut, E., A. Ingolfsson. 2000. Catastrophe avoidance models for hazardous materials route planning.
β€’
Transportation Science 34(2) 165-179.
β€’ Erkut, E., A. Ingolfsson. 2005. Transport risk models for hazardous materials. Operations Research Letters
33 81-89.
β€’
β€’ Erkut, E., V. Verter. 1998. Modeling of transport risk for hazardous materials. Operations Research 46(5)
625-642.
β€’ Gopalan, R., K. Kolluri, R. Batta, M. Karwan. 1990. Modeling equity of risk in the transportation of
β€’
hazardous materials. Operations Research 38(6) 961-973.
β€’ Hearn, D. W., M. V. Ramana. 1998. Solving congestion toll pricing models. P. Marcotte, S. Nguyen, eds.,
Equilibrium and Advanced Transportation Modeling. Kluwer Academic Publishers,
β€’
Boston/Dordrecht/London, 109-124.
β€’ Jin, H., R. Batta. 1997. Objectives derived from viewing hazmat shipments as a sequence of independent
bernoulli trials. Transportation Science 31(3) 252-261.
β€’
β€’ Joksimovic, D., M. C. Bliemer, P. H. Bovy. 2005. Optimal toll design problem in dynamic traffic networks
with joint route and departure time choice. Transportation Research Record: Journal of the Transportation β€’
Research Board 1923(1) 61-72.
β€’ Kang, Y., R. Batta, C. Kwon. 2013. Value-at-risk model for hazardous material transportation. Annals of β€’
Operations Research Accepted.
β€’ Kara, B., V. Verter. 2004. Designing a road network for hazardous materials transportation. Transportation
Science 38(2) 188-196.
β€’ Kuby, M., X. Zhongyi, X. Xiaodong. 1997. A minimax method for finding the k best differentiated paths. β€’
Geographical Analysis 29 298-313.
β€’ Kwon, C. 2011. Conditional Value-at-Risk Model for Hazardous Materials Transportation. S. Jain, R. R.
β€’ Creasey, J. Himmelspach, K. P. White, M. Fu, eds., Proceedings of the 2011 Winter Simulation
β€’
Conference, Grand Arizona Resort Phoenix, AZ. 1708-1714.
Marcotte, P., A. Mercier, G. Savard, V. Verter. 2009. Toll policies for
mitigating hazardous materials transport risk. Transportation Science
43(2) 228-243.
ReVelle, C., J. Cohon, D. Shobrys. 1991. Simultaneous siting and
routing in the disposal of hazardous wastes. Transportation Science
25(2) 138.
Saccomanno, F., A. Chan. 1985. Economic evaluation of routing
strategies for hazardous road shipments. Transportation Research
Record 1020 12-18.
Sivakumar, R. A., B. Rajan, M. Karwan. 1993. A network-based model
for transporting extremely hazardous materials. Operations Research
Letters 13(2) 85-93.
Toumazis, I., C. Kwon, R. Batta. 2013. Value-at-risk and conditional
value-at-risk minimization for hazardous materials routing.
R. Batta, C. Kwon, eds., Handbook of OR/MS Models in Hazardous
Materials Transportation (forthcoming). Springer.
U.S. Department of Transportation. 1999. Biennial report on hazardous
materials transportation calendar years 1996-1997. Tech. rep., Research
and Special Programs Administration Office of Hazardous Materials
Safety.
Wang, J., Y. Kang, C. Kwon, R. Batta. 2012. Dual toll pricing for
hazardous materials transport with linear delay. Networks and Spatial
Economics 12 147-165.
Yang, H., H. Huang. 2004. The multi-class, multi-criteria traffic network
equilibrium and systems optimum problem. Transportation Research
Part B 38 1-15.