基于交通网络几何和语义(交通)规则集成的公交换乘研究

换乘信息特别是基于地理信息系统技术的图文换乘信息服务,已经成为城市公共交通信息服务、线网规划和线路优化调整的重要指标与内容。但是公共交通线网具有特殊的网络特征和拓扑关系,它不同于城市道路网络,因此公共交通换乘不能简单应用于目前的最优路径算法,例如Dijkstra算法。本文将通过对公共交通线网的空间特征和语义(交通)规则分析,建立城市交通网络的几何和语义连通性的集成关系。几何连通性是语义连通性的基础和先决条件,而语义连通性是公共交通网络拓扑的核心。基于语义连通性的公共交通线网拓扑关系提升公共交通换乘算法的效率和信息准确度,任何两个站点之间的最优路径可以被迅速获取而不需要检索整个网络的几何拓扑信息。并且该最优换乘路径考虑到最少换乘次数、出行距离最短、费用最少、途经站点最少和换乘中最短步行距离等多目标换乘。

Public transportation transfer based on integration of geometric and semantic rules applied on transportation networks

Public transportation transfer information, especially map-text-based information service based on GIS (Geographical Information System) , has been a crucial criteria and content for urban public transportation information services, network planning and optimized adjustment. However, special network characteristics and topological relationships applied on public transportation networks are very different from urban street networks, thus optimal-path algorithms, such as Dijkstra, are not completely appliable to public transportation transfer. This paper proposed an integration of geometric and semantic (traffic-based rules) connectivity for urban transportation networks through analysis on spatial characteristics and traffic-based rules, i. e. , semantic rules applied on public transportation networks. Geometric connectivity is the precondition of semantic connectivity. Semantic connectivity is the core of public transportation network topology. Based on semantic connectivity, the topology relationship of public transportation networks promotes the efficiency and precision of transfer algorithms. The optimal path between any pair of stops can be swiftly located without a search of whole network geometric topology information. Moreover, the optimal transfer route consider multiple criteria, involving time of route changes , shortest-path, fare, number of stops passing by and shortest walking path during trip.