改进型CTM模型突发事件下的拥堵传播规律

Incident-based Traffic Congestion Propagation Mechanism With Improved CTM Model

通过引入元胞长度和元胞交通流密度2个参数,克服了原元胞传输模型(CTM)需要所有元胞统一长度的局限性.同时,结合传统的基本图方法和三相交通流理论,构建了考虑迟滞现象的MCTM模型,并研究了突发事件下快速路通行能力下降导致交通拥堵的形成及消散过程.仿真结果表明:模型能恰当反映城市快速路突发事件下的交通拥堵演化特点.

Cell transmission model （ CTM ） is equivalent to discrete approximation from macro kinetics LWR model, which can be utilized to capture such traffic dynamics as traffic flow shock waves and traffic jam. Two parameters including cell length and cell density were introduced into the MCTM to avoid the uniform cell length limitation. Meanwhile, combining traditional fundamental diagram approach and three-phase traffic theory, the hysteresis loop characteristics were combined into the MCTM model. This paper employed the MCTM model to investigate the traffic congestion forming and diffusing process due to road capacity drop-down in the traffic incident. Simulation result shows that this presented model can effectively meet the modeling demands of reality traffic congestion evolution characteristics with incidents in urban expressway system.