动态交通分配模型解的非唯一性问题

通过对动态交通分配模型和静态交通分配模型建模过程的比较，详细阐明了产生动态交通分配模型解的非唯一性问题的2个主要原因，即路段费用．流量函数的非单调性和先入先出（FIFO）原则约束条件的非凸性，在此基础上提出了在动态交通分配的路段费用函数中引入路段车辆数或路段密度的方法，建立了既能反映路段拥挤状态又具有单调特性的路段费用模型，从而显著提高了现有模型的求解效率．

Problem of Nonuniqueness of the Solution to Dynamic Traffic Assignment Model

Through the comparision of the modeling process between dynamic traffic assignment and static traffic assignment, this paper identifies that the noamnotony of the link cost - volume funtion and the nononvxity of the first - in - first - out(FIFO)constraints are the main two reasons which may cause the problem of nontalqueness of the solution to dynamic traffic assignment model. Thereafter, we introduce a link cost - density model which can reflect the traffic congestion well and also has the property of monotony. It is proved that the efficiency of the algorithm of the dynamic traffic assignment model can be greatly improved by using the link cost - density model.