To solve the problems of the multiple nodes

redundant data and unstable structure in traditional road-network models

a road-based model based on traffic network features and human's understanding of the road network

is constructed in this paper.In this model

the traffic and spatial attributes of the roads are expressed in detail

and traffic network is described by road intersection relationship.On the basis of lessening data and simplifying model structure

an improved A

*

algorithm is proposed.The results of the simulation experiment show that the proposed model and corresponding optimal path searching algorithm meet the needs of practical applications

besides

certain advantages can be found in storage cost of the model and search efficiency of the algorithm.