拥堵路网交通流均衡分配模型

为克服利用传统静态交通流分配模型分析拥堵道路网络交通流分配问题的不足,研究交通拥堵状态下静态拥堵交通流均衡分配模型.首先,基于拥堵路段上交通流特征,分析拥堵路段阻抗函数特点,包括满足拥堵路段上流量随车辆数增加而减少的特征;其次,分析拥堵状态下用户疏解路径选择行为,提出道路网静态拥堵交通流分配的用户均衡与系统最优原理;再次,构建道路网静态拥堵交通流用户均衡与系统最优分配模型,并证明模型与用户均衡原理的等价性、模型解的唯一性;最后,给出求解用户均衡模型的迭代加权求解算法.通过算例与传统静态交通流分配进行对比分析,结果表明:拥堵用户均衡分配模型与拥堵系统最优分配模型可以合理描述拥堵用户均衡原理与系统最优均衡原理,且拥堵用户均衡分配模型可以合理描述路网处于全拥堵状态下各路段实际通过流量.拥堵交通流分配模型可应用于由拥堵蔓延导致的局部全拥堵区域,可作为半拥堵静态交通流分配的核心部分之一.

The equilibrium model for congested traffic assignment in road networks

To overcome the weakness of using the traditional model for static traffic assignment in analyzing traffic assignment problems in congested road networks, equilibrium models for static congested traffic flow assignment in road networks are presented in this paper. First, based on the characteristics of the traffic flow in congested link, properties of the impedance function of congested road links were analyzed, which satisified that the traffic flow rates would decrease with increasing vehicles in congested links. Then, the route choice behavior in congested road networks was investigated. The equilibrium principles and mathematical models of user equilibrium and system optimum were proposed in the static form. Additionally, it was proved that the proposed user equilibrium model was equivalent to the user equilibrium principle and had a unique solution. Finally, the iterative weighted algorithm was given to solve the proposed user equilibrium model. The comparison between the proposed model and the tranditional traffic assignment was made on the basis of a simple example. Results show that the proposed user equilibrium and the system optimum models could reasonably describe the congested user equilibrium and system optimum principles, and the user equilibrium model could reasonably describe the real passing flow rate in the congested state. The proposed models could be applied to partial congested areas and used as one of the core parts of the semi-congested traffic assignment model.