A Parallel Calculation System for the Shortest Path in Traffic Network

2010 ◽  
Vol 143-144 ◽  
pp. 1240-1244 ◽  
Author(s):  
Lin Zhang ◽  
Zhao Sheng Yang ◽  
Hong Mei Jia ◽  
Bin Wang
Keyword(s):  
Shortest Path ◽  
Execution Time ◽  
Traffic Assignment ◽  
Dynamic Traffic Assignment ◽  
Traffic Network ◽  
Dynamic Traffic ◽  
Parallel Calculation ◽  
Network Decomposition ◽  
Decomposition Approach ◽  
Calculation System

The execution time of shortest path computing determines the efficiency and quality of dynamic traffic assignment. This paper focuses on the design of a parallel calculation system for the shortest path in traffic network aims to reduce the execution time of shortest path computing in dynamic traffic assignment. Here we mainly focus on the process of algorithm parallelization and network decomposition. As the core of the system, a two-queue parallel algorithm is designed for the shortest path in the traffic network which the recursive spectral bisection decomposition approach is employed to separate the network into several parts and the algorithm acts on every sub-network on each processor. The proposed system are experimented on real traffic network and a set of policies are employed that the number of processors is designed in each policy in the study case, and the performances of the parallel calculation system are discussed, the proposed algorithm is proved to be the efficient and effective.

scholarly journals Distributed Dynamic Traffic Modeling and Implementation Oriented Different Levels of Induced Travelers

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Yan Liu ◽  
Yao Yu
Keyword(s):  
Traffic Management ◽  
Traffic Assignment ◽  
Dynamic Traffic Assignment ◽  
Distributed Model ◽  
Traffic Network ◽  
Dynamic Traffic ◽  
Assignment Method ◽  
Proposed Model ◽  
Network Operation ◽  
Different Levels

In order to respond to the variable state of traffic network in time, a distributed dynamic traffic assignment strategy is proposed which can improve the intelligent traffic management. The proposed dynamic assignment method is based on utility theory and is oriented to different levels of induced users. A distributed model based on the marginal utility is developed which combines the advantages of both decentralized paradigm and traveler preference, so as to provide efficient and robust dynamic traffic assignment solutions under uncertain network conditions. Then, the solution algorithm including subroute update and subroute calculation is proposed. To testify the effectiveness of the proposed model in optimizing traffic network operation and minimizing traveler’s cost on different induced levels, a sequence numerical experiment is conducted. In the experiment, there are two test environments: one is in different network load conditions and the other is in different deployment coverage of local agents. The numerical results show that the proposed model not only can improve the running efficiency of road network but also can significantly decrease the average travel time.

Routing Profile Updating Strategies for Online Hybrid Dynamic Traffic Assignment Operation

2003 ◽  
Vol 1857 (1) ◽  
pp. 39-47 ◽  
Author(s):  
Yi-Chang Chiu ◽  
Hani S. Mahmassani
Keyword(s):  
Real Time ◽  
System Performance ◽  
Traffic Assignment ◽  
Dynamic Traffic Assignment ◽  
A Priori ◽  
Traffic Network ◽  
Route Guidance ◽  
Dynamic Traffic ◽  
Simulation Experiments ◽  
Principal Mechanism

An online routing profile updating automaton (ORPUA) approach is introduced as a principal mechanism for operating an online hybrid dynamic traffic assignment (DTA) system for real-time route guidance in a traffic network. The hybrid DTA approach integrates the centralized and the decentralized DTA frameworks by partitioning the set of guided users into two classes according to an initial routing profile (IRP). One class receives the centralized DTA guidance, while the other follows the decentralized DTA routing. ORPUA takes the a priori IRP and updates the guidance supplied to vehicles in a real-time fashion according to the unfolding network conditions and relative performance of the two classes of users. It does not anticipate the future network conditions; instead, it reacts to them and optimizes the overall system performance by improving the performance of the underperforming class of vehicles. Simulation experiments illustrate ORPUA’s potential in maintaining desirable system performance and robustness in most of the demand-supply scenarios considered.

scholarly journals The Analysis of Braess’ Paradox and Robustness Based on Dynamic Traffic Assignment Models

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Bai-Bai Fu ◽  
Chun-Xue Zhao ◽  
Shu-bin Li
Keyword(s):  
Traffic Assignment ◽  
Dynamic Traffic Assignment ◽  
Traffic Network ◽  
Dynamic Traffic ◽  
Braess Paradox ◽  
Traffic Demand ◽  
Demand Changes ◽  
Relationship Of ◽  
Assignment Models ◽  
The Relationship

The investigation of the paradox and robustness about the traffic network is an important branch of the traffic assignment. In this paper, Braess’ paradox and robustness of the dynamic traffic network are analyzed by the dynamic traffic assignment models. In addition, the relationship of total costs with different traffic assignment models is discussed. The results show that the paradox only occurs in certain range; the robustness of the network and the relationship of total traffic costs are changed as the traffic demand changes, which provides theoretical guidance for the urban transportation planning.

Sign in / Sign up

Export Citation Format

Share Document