Journal of South China University of Technology(Natural Science Edition) ›› 2022, Vol. 50 ›› Issue (10): 11-18.doi: 10.12141/j.issn.1000-565X.220008

Special Issue: 2022年交通运输工程

• Traffic & Transportation Engineering • Previous Articles     Next Articles

Construction and Application of Cellular Automaton Model of Traffic Flow in Freeway Diverging and Merging Areas

QI Weiwei1 MA SiweiZHOU Nanjie2   

  1. 1.School of Civil Engineering and Transportation,South China University of Technology,Guangzhou 510640,Guangdong,China
    2.Guangzhou Northring Intelligent Transport Technology Co. Ltd. ,Guangzhou 510030,Guangdong,China
  • Received:2022-01-05 Online:2022-10-25 Published:2022-05-06
  • Contact: 周南杰(1973-),男,工程师,主要从事高速公路营运和养护工程管理研究. E-mail:13802756582@139.com
  • About author:漆巍巍(1985-),男,博士,副教授,主要从事交通系统优化、交通安全管控研究。E-mail:ctwwqi@scut.edu.cn.
  • Supported by:
    the National Natural Science Foundation of China(52072131);the Key Research Projects of General Colleges and Universities in Guangdong Province(2019KZDXM009);the Natural Science Foundation of Guangdong Province(2022A1515010123)

Abstract:

The operation and management optimization schemes of freeway always need to be formulated according to the traffic capacity of bottleneck sections. Due to the complexity of the traffic flow characteristics of the bottleneck sections of freeway, the current general calculation formulas of the traffic capacity are limited to many assumptions, and the accuracy is not high and the error is large. This paper attempted to construct a calculation method of traffic capacity in freeway bottleneck sections and verify it by actual measurement. Firstly, UAV technology and software Tracker were used for aerial video recording and dynamic identification and 680 groups of traffic flow data for car-following and lane-changing on freeway was obtained, including position, speed, acceleration, headway and other parameters. Then, the probability models and rule models of lane-changing considering driver characteristics were established according to the obtained traffic flow parameters, and the classical car-following model GHR was calibrated. Finally, a simulation application model of freeway traffic flow based on cellular automaton theory was constructed by the partitioning method, the acceleration requirements of following vehicles were characterized with GHR model, and the effectiveness of the model was verified by the indicators of vehicle lane-changing times and hourly traffic volume with error rates of 12.06% and 3.19%, respectively. The results show that this model can effectively calculate the capacity of freeway diverging and merging areas and design the road parameters such as the length of speed-change lane. In this case, a traffic flow simulation test was conducted on Cencun interchange sections of Guangzhou Northring Freeway, in which the road geometry characteristics, vehicle arrival conditions and traffic flow operation mechanism were simulated. The capacity of the diverging and merging areas is 5 456 and 5 253 pcu/h, respectively, and the optimization design values for the length of speed-change lanes in the diverging and merging areas are 125 and 200 m, respectively. The cellular automaton model of traffic flow constructed in this paper provides scientific basis for microscopic traffic flow simulation and road parameters design of freeway diverging and merging areas, and helps to improve the level of service and operational quality.

Key words: freeway, diverging and merging areas, cellular model, traffic flow simulation, capacity

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