【摘要】 以确定性交通网络用户均衡问题为研究对象,在系统分析了确定性用户均衡问题的模型与优化条件的基础上,提出了可变步长投影梯度方法,并把它用于交通量分配问题.该方法把数学方法与交通工程实践相结合,避免了传统算法中可能出现的解的振荡现象.根据路径费用的大小决定路径解集的取舍,最终可以找到与各OD对相对应的多条最短路径,这个思想把Wardrop原则直接用于分配方法的设计,使路径选择者、交通工程师直观地体会到交通路径选择的多样性.实例验证了算法的合理性与丰富性.更多还原

【Abstract】 This paper proposes a method for solving to the deterministic user equilibrium assignment problem.On the basis of gradient projection algorithm (GP),a variant of GP with adaptive step is developed for traffic assignment.The incorporates mathematical programming into traffic engineering,and efficiently avoids the oscillation phenomenon that possibly happens in the conventional GP solution.Due to the direct application of Wardrop’s principle to the solution design,the GP with the variable step shows that multi-shortest paths maybe exist in any OD pair,which is especially useful for route choice decision_makers and traffic engineers.Two numerical examples illustrate the efficiency of the proposed solution and its application to route choice.更多还原