Traffic-monitoring can efficiently promote better urban planning and encourage better use of public transport. The investment of traffic-monitoring system will bring huge social and economic benefits by reducing congestion and pollution. Based on the wireless sensor network (WSN) technique, this paper investigates the problem of efficiently monitoring, collecting, and disseminating traffic information in an urban setting. We design the architecture of WSN-based traffic-monitoring system and specify the phases of the traffic information acquisition and delivery in the context of WSN environment. A novel data-centric routing algorithm is proposed for data delivery, in which multiple routing-related information are adopted for routing decision making. Simulation results have shown the good performance of the proposed routing scheme compared with other traditional schemes. © 2013 IEEE.