After presenting weaknesses of several classic routing protocols applied in vehicular ad hoc networks (VANETs) by a qualitative comparison,this paper proposes a novel self-adaptive routing protocol,named ARPP.With respect to the specific characteristics of VANETs,the proposed routing protocol adopts a dynamic topology establishment and time-varying control message sending mechanism.A direction-based forwarding strategy and a specific warning solution enhance the routing performance in ARPP.Simulation results show that the ARPP protocol outperforms the classic AODV in urban vehicle environment.