路段容量约束弹性需求交通均衡分配近似算法

本文研究了带路段容量约束弹性需求用户均衡交通分配问题及其近似解法.采用超需求模型将弹性需求转化为固定需求,提出了一种带路段容量约束弹性需求用户均衡交通分配近似算法.该算法在迭代过程中,通过不断自适应调节排队延误因子、误差因子来近似真实路段行驶时间,使路段流量逐步满足约束条件,最终达到广义用户均衡.这种方法克服了容量约束弹性需求用户均衡分配计算量大及随机分配法要求枚举所有路径的困难.随后证明了算法的收敛性,并对一个小型路网进行了数值试验.

APPROXIMATE ALGORITHM FOR ELASTIC DEMAND TRAFFIC EQUILIBRIUM ASSIGNMENT PROBLEM WITH LINK CAPACITY CONSTRAINTS

This paper studies the elastic demand traffic equilibrium assignment problem with link capacity constraints.We analyze the differences of link travel time and traffic demand between the link capacity constraints model and the one with link capacity unconstraint.The elastic demand model is transformed as fixed one according to excess demand formulation and we propose an approximate algorithm for the model to circumvent the costly solution of the constrained assignment problem.The algorithm ensures gradually the links flow lower than corresponding capacity and trends to generalized elastic demand user equilibrium by approximating actual link travel time and adaptively regulating the delay and error factors in each iteration.It is superior to stochastic equilibrium methods by avoiding paths numeration.Both the convergence result and the numerical example show the algorithms are effective and efficient.