基于转向的Logit交通分配算法

为避免交通分配中传统的网络扩展法在处理转向延误时的缺陷,通过分析网络基本要素节点、路段和转向之间的拓扑关系,借鉴Dial算法的基本框架,设计了一个基于转向的Logit交通分配算法。该算法以源点至路段的含转向延误的最短路径长度为依据处理各条路段,正向计算转向权重,反向分配路段流量和转向流量。算法计算结果与Logit路径流量和Dial算法数据相一致,该算法可直接求解既满足Logit路径选择概率又考虑转向延误对交通分配影响的路段流量和转向流量模式,而且Dial算法是其在转向延误为零时的一个特例。

Turn-based algorithm for Logit traffic assignment

To overcome the shortcomings in traditional network-expanding method for handling turn delays in traffic assignment,a turn-based algorithm for Logit traffic assignment was developed with a similar framework of Dial algorithm,which was based on the topological relationships between network element nodes,links and turns.According to the origin-to-link-type shortest path distances with turn delays,all links were processed,turn weights were computed forward,and link flows and turn flows were assigned backward by the algorithm.Computation result shows that the flow assignment of the algorithm is identical to Logit-based path flows and Dial's algorithm data,the algorithm directly computes link flow and turn flow patterns,which not only agrees with Logit route-choice probability,but also counts for the effect of turn delays on traffic assignment,and Dial algorithm is a special case of the algorithm when all turn delays vanish.5 tabs,3 figs,10 refs.