The e-map is the most important part in Vehicle Navigation System. Functional requirements for the road map database vary in different navigation phases. Though there are various road network models, their traditional road network structures, unfortunately, do not solve the problem well. Therefore this paper proposes a featurebased data model with two level structures. The level-one is a feature-oriented geometry network used for map showing the level-two is a node-link based logical network for route planning. Further, a two-layer network topological structure in logical network is presented, which accords with the practical driving habit better than traditional way treating the entire road network as one graph.

No abstract