An Algorithm for Building Full Topology

Traditional polygon-arc-node topological relationships (TRs) is standard in vector GIS. That has been explicitly represented by many commercial GIS systems. In the case of Intelligent Transportation System (ITS), a full topology is defined by an international standard with which road network data are topologically structured. One important part of ITS application is place searching and path finding that is based on the connectivity of road segments and TRs between road segments and certain area features, such as zoos. Therefore, we need to construct arc-node topology to record From-Node and End-Node of one edge, node-arc topology to record edges at the node, and ‘special’ area topology. The former two are similar to the definition in the past, but the last one is different. Since the required topologies in ITS application are different from that of the traditional methods, the required algorithm is different. Based on the analysis of the requirements and characteristics of ITS application, the present paper proposes an algorithm for building the topological relationships between spatial objects in road network. Compared with other methods, the topologies defined in this paper can describe TRs between spatial objects in road network more accurately; the present algorithm is simplified and more efficient. Experiments demonstrate that the efficiency of the proposed algorithm is improved by 150% in contrast with other methods.