scholarly journals A Comparison of Transportation Network Resilience under Simulated System Optimum and User Equilibrium Conditions

2006 ◽  
Author(s):  
Pamela Murray-tuite
Keyword(s):  
Transportation Network ◽  
User Equilibrium ◽  
Network Resilience ◽  
System Optimum ◽  
Equilibrium Conditions ◽  
Simulated System

A THEORY OF MULTIPLE VEHICLE TYPE DYNAMIC MARGINAL COST CONSIDERING DEPARTURE TIME CHOICES

Transport ◽  
2010 ◽  
Vol 25 (3) ◽  
pp. 307-313
Author(s):  
Shu-Guang Li ◽  
Qing-Hua Zhou
Keyword(s):  
Marginal Cost ◽  
User Equilibrium ◽  
System Optimum ◽  
Equilibrium Conditions ◽  
Traffic Demand ◽  
Vehicle Type ◽  
Departure Time ◽  
Single Vehicle ◽  
Link Model ◽  
Analytic Expression

The analysis of single vehicle type dynamic marginal cost is extended to multiple vehicle type dynamic one based on time‐dependent multiple vehicle type queue analysis at a bottleneck. First, a dynamic link model to rep‐ resent the interactions between cars and trucks is provided. Then, the analytic expression of a multiple vehicle type dynamic marginal cost function considering departure time choices is deduced under congested and un‐congested conditions and consequently, a dynamic toll function is given. A heuristic algorithm is introduced to solve multiple vehicle type dynamic queues and toll under system optimum and user equilibrium conditions taking into account traveler's departure time. A numerical example shows that a dynamic congestion toll can diminish queues and improve system conditions when traffic demand is not changed.

scholarly journals Bounding the Inefficiency of the Multiclass, Multicriteria C-Logit Stochastic User Equilibrium in a Transportation Network

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Lekai Yuan ◽  
Xi Zhang ◽  
Chaofeng Shi
Keyword(s):  
Variational Inequality ◽  
Variational Inequalities ◽  
Stochastic System ◽  
Traffic Congestion ◽  
Transportation Network ◽  
User Equilibrium ◽  
Upper Bounds ◽  
Choice Probability ◽  
Stochastic User Equilibrium ◽  
System Optimum

We derive the exact inefficiency upper bounds of the multiclass C-Logit stochastic user equilibrium (CL-SUE) in a transportation network. All travelers are classified on the basis of different values of time (VOT) into M classes. The multiclass CL-SUE model gives a more realistic path choice probability in comparison with the logit-based stochastic user equilibrium model by considering the overlapping effects between paths. To find efficiency loss upper bounds of the multiclass CL-SUE, two equivalent variational inequalities for the multiclass CL-SUE model, i.e., time-based variational inequality (VI) and monetary-based VI, are formulated. We give four different methods to define the inefficiency of the multiclass CL-SUE, i.e., to compare multiclass CL-SUE with multiclass system optimum, or to compare multiclass CL-SUE with multiclass C-Logit stochastic system optimum (CL-SSO), under the time-based criterion and the monetary-based criterion, respectively. We further investigate the effects of various parameters which include the degree of path overlapping (the commonality factor), the network complexity, degree of traffic congestion, the VOT of user classes, the network familiarity, and the total demand on the inefficiency bounds.

scholarly journals A Based-Bottleneck Multiple Vehicle Type Dynamic Marginal Cost Model and Algorithm

1970 ◽  
Vol 24 (5) ◽  
pp. 381-387
Author(s):  
Shuguang Li
Keyword(s):  
Marginal Cost ◽  
Cost Model ◽  
User Equilibrium ◽  
System Optimum ◽  
Equilibrium Conditions ◽  
Vehicle Type ◽  
Flow Speeds ◽  
Single Vehicle ◽  
Link Model ◽  
Analytic Expression

Single vehicle type dynamic marginal cost model is extended to multiple vehicle type dynamic one based on time-dependent multiple vehicle type queue analysis at a bottleneck. A dynamic link model is presented to model interactions between cars and trucks, given the link consists of two distinct segments. The first segment is the running segment on which cars (trucks) run at their free-flow speeds and the second segment is the exit queue segment. A car or a truck is assumed to be a point without length. The class-specific pi parameter is used to transform the effect of truck into passenger car equivalents, so the exit flow of cars and trucks can be calculated according to the exit capacity of a bottleneck. The analytic expression of multiple vehicle type dynamic marginal cost function is deduced under congested and uncongested conditions. Then a heuristic algorithm is presented in solving multiple vehicle type dynamic queues, tolls under system optimum and user equilibrium conditions. The numerical example illustrates the simplicity and applicability of the proposed approach.

scholarly journals Traffic Paradox Under Different Equilibrium Conditions Considering Elastic Demand

2019 ◽  
Vol 31 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Qiang Tu ◽  
Lin Cheng ◽  
Dawei Li ◽  
Jie Ma ◽  
Chao Sun
Keyword(s):  
Traffic Management ◽  
Network Performance ◽  
Transportation Network ◽  
Travel Cost ◽  
User Equilibrium ◽  
Stochastic User Equilibrium ◽  
Equilibrium Conditions ◽  
Traffic Demand ◽  
Travel Costs ◽  
Cost Sensitivity

Traffic paradox is an important phenomenon which needs attention in transportation network design and traffic management. Previous studies on traffic paradox always examined user equilibrium (UE) or stochastic user equilibrium (SUE) conditions with a fixed traffic demand (FD) and set the travel costs of links as constants under the SUE condition. However, traffic demand is elastic, especially when there are new links added to the network that may induce new traffic demand, and the travel costs of links actually depend on the traffic flows on them. This paper comprehensively investigates the traffic paradox under different equilibrium conditions including the user equilibrium and the stochastic user equilibrium with a fixed and elastic traffic demand. Origin-destination (OD) mean unit travel cost (MUTC) has been chosen as the main index to characterize whether the traffic paradox occurs. The impacts of travelers’ perception errors and travel cost sensitivity on the occurrence of the traffic paradox are also analyzed. The conclusions show that the occurrence of the traffic paradox depends on the traffic demand and equilibrium conditions; higher perception errors of travelers may lead to a better network performance, and a higher travel cost sensitivity will create a reversed traffic paradox. Finally, several appropriate traffic management measures are proposed to avoid the traffic paradox and improve the network performance.

scholarly journals Bi-Criteria System Optimum Traffic Assignment in Networks With Continuous Value of Time

1970 ◽  
Vol 25 (2) ◽  
pp. 119-125 ◽  
Author(s):  
Xin Wang ◽  
Hai-Jun Huang
Keyword(s):  
Flow Pattern ◽  
Equilibrium Model ◽  
Transportation Network ◽  
System Optimization ◽  
User Equilibrium ◽  
Value Of Time ◽  
Elastic Demand ◽  
System Optimum ◽  
Pricing Scheme ◽  
Objective Model

For an elastic demand transportation network with continuously distributed value of time, the system disutility can be measured either in time units or in cost units. The user equilibrium model and the system optimization model are each formulated in two different criteria. The conditions required for making the system optimum link flow pattern equivalent to the user equilibrium link flow pattern are derived. Furthermore, a bi-objective model has been developed which minimizes simultaneously the system travel time and the system travel cost. The existence of a pricing scheme with anonymous link tolls which can decentralize a Pareto system optimum into the user equilibrium has been investigated.

scholarly journals Analyzing the Formation Mechanism of Cross-City Transportation Network Resilience

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Liang Wang ◽  
Xiaolong Xue ◽  
Weirui Xue ◽  
Beile Zhao
Keyword(s):  
Theoretical Model ◽  
Formation Mechanism ◽  
Transportation Network ◽  
Network Resilience ◽  
Railway Network ◽  
Network Nodes ◽  
General Meaning ◽  
Important Position ◽  
And Function ◽  
Constituent Elements

The formation mechanism of cross-city transportation network resilience occupies an important position in cross-city transportation network resilience management. This study analyzes the constituent elements of the cross-city transportation network and their interrelationships, and the connotation of cross-city transportation network resilience is defined from the general meaning of system resilience. Combining with the connotation of cross-city transportation network resilience, the specific formation process of cross-city transportation network resilience is analyzed and summarized from three stages, including resisting disturbance, absorbing disturbance, and function recovery. Taking cross-city transportation network nodes and systems as specific objects, the static and dynamic formation path of cross-city transportation network resilience is condensed. Based on the standard linear solid model, a theoretical model is constructed and solved for revealing the formation mechanism of cross-city transportation network resilience. Finally, the theoretical model of cross-city transportation network resilience proposed in this study is used for analyzing the China railway network resilience.

scholarly journals A Two-Phase Gradient Projection Algorithm for Solving the Combined Modal Split and Traffic Assignment Problem with Nested Logit Function

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Seungkyu Ryu ◽  
Anthony Chen ◽  
Songyot Kitthamkesorn
Keyword(s):  
Large Scale ◽  
Traffic Assignment ◽  
Transportation Network ◽  
User Equilibrium ◽  
Gradient Projection ◽  
Projection Algorithm ◽  
Nested Logit ◽  
Two Phase ◽  
Phase Gradient ◽  
Modal Split

This study provides a gradient projection (GP) algorithm to solve the combined modal split and traffic assignment (CMSTA) problem. The nested logit (NL) model is used to consider the mode correlation under the user equilibrium (UE) route choice condition. Specifically, a two-phase GP algorithm is developed to handle the hierarchical structure of the NL model in the CMSTA problem. The Seoul transportation network in Korea is adopted to demonstrate an applicability in a large-scale multimodal transportation network. The results show that the proposed GP solution algorithm outperforms the method of the successive averages (MSA) algorithm and the classical Evan’s algorithm.

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