交通分配起点算法的实证研究

以交通网络为对象,研究求解均衡网络模型的起点算法原理及其实际应用.起点算法是一种基于路径树的交通网络流量分配方法,它按照交通分布起点把交通分配问题分解成若干个子过程.若干个子过程在网络空间的叠加,形成交通网络流量.在每个子过程中,在具有同一起点的若干起终点对之间,所有路径满足Wardrop原则.在比较不同收敛标准的基础上,提出最大-最小路径费用差作为起点算法的收敛准则.选用国内外不同规模的5个城市交通网络数据,对起点算法进行测试,结果表明,起点算法具有很好的稳定性,能够满足任何给定的精度要求.采用最大-最小路径费用差作为起点算法的收敛标准,能够真实反映起点算法的卓越性能,精确表现交通网络均衡原则.

Empirical Analysis on Origin-based Algorithm for Traffic Assignment

Theoretical mechanism and empirical analysis of origin-based algorithm are addressed for user equilibrium traffic assignment. Origin-based algorithm decomposes traffic assignment problem into some sub-processes according to the origin of traffic demand and obtains solution of flow by overlapping them on the network. All paths among the same origin-destination pair in the sub-process satisfy Wardrop principle. On the basis of comparing different convergence criteria, the paper proposes max-min cost difference bound as convergence criterion suitable for origin-based algorithm, and makes verifications over five example networks. The experimental result shows that origin-based algorithm can satisfy any precision requirement, and has superior stability to the traditional one. Max-min cost difference bound can exhibit the efficiency of origin-based algorithm and really illustrates the traffic network equilibrium principle.