Map-matching algorithm based on the index mechanism

The emergency vehicle equipped with GPS plays an important role in the highway rapid response behavior. In order to remove the display error produced by the GPS locating data and the E-map, the matching algorithm has been put forward based on the map index and the shortest distance algorithm. According to the difference between highways and urban roads, the proposed map-matching algorithm links the vehicle location information with the road information of E-map database, achieving the effective and rapid search of the road, thus, the vehicle’s position relative to E-map can be determined. In order to validate the map-matching algorithm, the simulation program is developed using VB and MapObject module. The results of test show that the algorithm can greatly decrease the influence of the locating error and reduce the ratio of mismatch.