A wave-oriented variable cell transmission model in an urban road

2021 ◽  
Author(s):  
Zeyu Shi ◽  
Yangzhou Chen ◽  
Jingyuan Zhan ◽  
Xiangyu Guo ◽  
Shuke An
Keyword(s):  
Traffic Flow ◽  
Urban Traffic ◽  
Transmission Model ◽  
Hybrid Automata ◽  
State Variables ◽  
Cell Transmission Model ◽  
Fundamental Diagram ◽  
Influence Area ◽  
Cell Transmission ◽  
The Waves

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.

Width-Based Cell Transmission Model for Heterogeneous and Undisciplined Traffic Streams

2019 ◽  
Vol 2673 (5) ◽  
pp. 682-692 ◽  
Author(s):  
Afzal Ahmed ◽  
Satish V. Ukkusuri ◽  
Shahrukh Raza Mirza ◽  
Ausaja Hassan
Keyword(s):  
Traffic Flow ◽  
Behavior Modeling ◽  
Flow Diagram ◽  
Transmission Model ◽  
Flow Density ◽  
Cell Transmission Model ◽  
Fundamental Diagram ◽  
Flow Models ◽  
Cell Transmission ◽  
Traffic Flow Models

Traffic streams in many developing countries consist of various modes of transport, with high heterogeneity in driver behavior. Modeling these types of traffic streams, in which traffic rules (speed limit, lane discipline, etc.) are not strictly followed, is a complex task. A review of the existing literature shows that there is a lack of traffic flow models that model the behavior of heterogeneous and undisciplined traffic streams. Like other undisciplined traffic streams, there are no speed limits (hence no speed enforcement) on most of the roads in Karachi, Pakistan. Lane discipline is also not observed by drivers, which results in a varying number of traffic lanes on a road. Therefore, most of the existing traffic flow models/simulation packages developed for disciplined traffic streams cannot appropriately model traffic streams without lane discipline. This research proposes a width-based cell transmission model (WCTM) by developing a fundamental flow-density diagram whose parameters are a function of the road width. Extensive field data have been collected from a selected arterial in Karachi for development of the fundamental traffic flow diagram. The values of the computed parameters are significantly different than the values reported in the literature. The piecewise-linear flow-density relation is developed by optimally estimating the breakpoints. Results show that the quadrilateral and pentagonal-shaped fundamental diagrams fit better with the collected data in comparison with the triangular-shaped fundamental diagram. The proposed WCTM is applied to selected segments of an arterial and results show that the WCTM was able to accurately model different traffic conditions.

scholarly journals Research on Analysis Method of Traffic Congestion Mechanism Based on Improved Cell Transmission Model

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Hongzhao Dong ◽  
Shuai Ma ◽  
Mingfei Guo ◽  
Dongxu Liu
Keyword(s):  
Traffic Flow ◽  
Traffic Congestion ◽  
Road Network ◽  
Simulation Experiment ◽  
Transmission Model ◽  
Spatial Diffusion ◽  
Cell Transmission Model ◽  
Analysis Method ◽  
Proposed Model ◽  
Cell Transmission

To analyze the spreading regularity of the initial traffic congestion, the improved cell transmission model (CTM) is proposed to describe the evolution mechanism of traffic congestion in regional road grid. Ordinary cells and oriented cells are applied to render the crowd roads and their adjacent roads. Therefore the traffic flow could be simulated by these cells. Resorting to the proposed model, the duration of the initial traffic congestion could be predicted and the subsequent secondary congestion could be located. Accordingly, the spatial diffusion of traffic congestion could be estimated. At last, taking a road network region of Hangzhou city as an example, the simulation experiment is implemented to verify the proposed method by PARAMICS software. The result shows that the method could predict the duration of the initial congestion and estimate its spatial diffusion accurately.

Urban Traffic Jam Simulation Based on the Cell Transmission Model

2008 ◽  
Vol 11 (1) ◽  
pp. 43-64 ◽  
Author(s):  
Jiancheng Long ◽  
Ziyou Gao ◽  
Xiaomei Zhao ◽  
Aiping Lian ◽  
Penina Orenstein
Keyword(s):  
Urban Traffic ◽  
Transmission Model ◽  
Cell Transmission Model ◽  
Traffic Jam ◽  
Simulation Based ◽  
Cell Transmission

Modelling Heterogeneous and Undisciplined Traffic Flow using Cell Transmission Model

2020 ◽  
Vol 02 (01) ◽  
pp. 01-05
Author(s):  
Afzal Ahmed ◽  
Mir Shabbar Ali ◽  
Toor Ansari
Keyword(s):  
Traffic Flow ◽  
Traffic Simulation ◽  
Flow Diagram ◽  
Transmission Model ◽  
Flow Density ◽  
Cell Transmission Model ◽  
Flow Models ◽  
Simulation And Optimization ◽  
Cell Transmission ◽  
Traffic Flow Models

This research calibrates Cell Transmission Model (CTM) for heterogeneous and non-lane disciplined traffic, as observed in Pakistan and some other developing countries by constructing a flow-density fundamental traffic flow diagram. Currently, most of the traffic simulation packages used for such heterogonous and non-lane-disciplined traffic are not calibrated for local traffic conditions and most of the traffic flow models are developed for comparatively less heterogeneous and lane-disciplined traffic. The flow-density fundamental traffic flow diagram is developed based on extensive field data collected from Karachi, Pakistan. The calibrated CTM model is validated by using actual data from another road and it was concluded that CTM is capable of modelling heterogeneous and non-lane disciplined traffic and performed very reasonably. The calibrated CTM will be a useful input for the application of traffic simulation and optimization packages such as TRANSYT, SIGMIX, DISCO, and CTMSIM.

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