Research On The Urban Road Network Model

As the problem of transportation is increasing today, the intelligent transportation system is arousing more and more attention. Being the basic of the intelligent transportation system, the road network model becomes the focus of the research. At present, road network as a spatial network is abstracted to be a graph in most of the researches. Considering the usual graph cannot meet the demand of the ample features attributes and complexity of the road network, there appear node-link model and pseudo-dual graph model. These models can describe the part transport restriction, but the increment of the node's and the arc's quantity makes the cost of the graph algorithm increase greatly.To solve the problem above, a super-node model is presented. This method concentrates the turn restriction on each node and uses restriction matrix representation. Based on perfecting the super-node model, this thesis made some implement as follows: 1. The extent UML instrument is used to model the network, the symbol representations of the real world objects are described with graphic. 2. A data model suited to the conceptual model is proposed. Data redundancy is reduced by merge cost-arcs and the node identifications of constraint-matrix. 3. Some of the query algorithm based on the road network is mended with integrating the research of spatial data index.Simulation experiments on storage space and query support are processed on super-node model and node-link model in the last of this thesis. The results show that the storage cost of the super-node representation method is less than that of the latter, and the Continuous nearest neighbor search and range query on the super-node model is more efficient than the latter. The experiments indicate that the super-node model can not only represent the road network and transportation information well, but also lead to an efficient query process.