VANET is a special case of MANET , and will play an increasingly important role in road traffic management. VANET networks have different motion characters in different scenarios. Through the extension of the current network simulation software NS2, the different simulation scenarios were set up. Several typical Ad hoc routing protocols were simulated and analyzed in the streets and highways scenarios. Simulation results show that AODV and DSR have a relatively stable performance. The results have value in the research and application of VANET to traffic management.