A traffic light extension to Cell Transmission Model for estimating urban traffic jam

To describe the dynamics of traffic flow in the urban link accurately, the waves which generate at intersections are adopted as the influencing factors of traffic flow. Based on the urban traffic waves, a wave-oriented variable cell transmission model (WVCTM) is proposed to illustrate the urban traffic flow. In this model, the average density and length are the state variables. The cells are divided by traffic waves. The upstream cell is the influence area of the waves at the upstream intersection, the downstream cell is the influence area of the waves at the downstream intersection, and the rest is the mediate cell. Consistent with the fundamental diagram and the cell division, the traffic states of urban links are divided into six modes. The variation of modes is explained by hybrid automata. Finally, an experiment is designed to verify the feasibility of WVCTM. The data in the experiment come from the actual scene. Compared with the cell transmission model (CTM) and variable-length CTM (VCTM), WVCTM possesses the valuable performance to predict the traffic states. Likewise, it is rational that WVCTM can correctly illustrate the urban traffic flow.

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Estimation of Urban Traffic State Based Velocity Cell Transmission Model

2020 Chinese Automation Congress (CAC) ◽

10.1109/cac51589.2020.9327817 ◽

2020 ◽

Author(s):

Zhonghe He ◽

Hongjia Wang ◽

Renchi Shao

Keyword(s):

Urban Traffic ◽

Transmission Model ◽

Cell Transmission Model ◽

Traffic State ◽

Cell Transmission

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An Innovative Eigenvector-Based Method for Traffic Light Scheduling

Journal of Advanced Transportation ◽

10.1155/2020/1462430 ◽

2020 ◽

Vol 2020 ◽

pp. 1-14

Author(s):

Mohammad Amin Soltani-Sarvestani ◽

Zohreh Azimifar ◽

Alexander Wong ◽

Ali Akbar Safavi

Keyword(s):

Transmission Model ◽

Cell Transmission Model ◽

Eigenvector Centrality ◽

Traffic Light ◽

Fundamental Diagram ◽

Scheduling System ◽

Traffic Jam ◽

Grid Networks ◽

Traffic Light Scheduling ◽

Relation Matrix

This paper introduces two traffic light strategies to control traffic and avoid traffic jam in urban networks. One strategy is a new traffic light scheduling system, which controls traffic light using local variables (waiting time and number of vehicle on links) but has a global impact on the traffic, using shared variables between neighbour intersections. The proposed traffic light scheduling system is designed based on eigenvector centrality of intersection relation matrix. The intersection relation matrix is a new representation of a junction which indicates the traffic relation between intersection’s links and adjacent intersections. The second contribution is expanding a new dual mode traffic light strategy (namely, Exit Status Traffic Light (ETL)), which notifies the drivers whether they are allowed to exit a street or not. In other words, vehicles are allowed to enter a street in both red and green ETL, but they are not allowed to exit the street for a long time in red ETL (while traffic is heavy in the subnetwork). The ETL gives a chance to relax traffic in a subnetwork and avoid traffic jam. The effectiveness of the proposed strategy is analysed and evaluated by a number of simulations on three-way grid networks. Two-way rectangular grid networks are modelled via a cell transmission model (CTM). The macroscopic fundamental diagram (MFD) and the number of jammed cells are compared with two state-of-the-art methods.

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