The complexity of a real road network structure of a city and the variability of its real traffic information make a city’s intelligent transportation system (ITS) hard to meet the needs of the city’s vehicle navigation. This paper has proposed a simplified real-time road network model which can take into account the influence of intersection delay on the guidance for vehicles but avoid the calculation of intersection delay and troublesome collection of a city’s traffic data. Based on the new model, a navigation system has been presented, which can plan a dynamic optimal path for a vehicle according to the real-time traffic data received periodically from the city’s traffic center. A simulated experiment has been given. Compared with previous real-time road network models, the new model is much simpler and more effective on the calculation of vehicle navigation.

How to model a dynamic road network has great practical significance in a vehicle navigation system. This paper has proposed a simplified time-division based on road network model which implicitly takes into account the delay time at various intersections, the degree of a road congestion and the different road quality, but avoids a complicated calculation and collection for these traffic data. An improved Dijkstra algorithm based on the new model has also been given. The simulation results show that the model can work well and the algorithm is efficient.