Reliable traffic message communication is one of the most essential goals for implementing secure vehicular ad hoc networking environment. In order to support secure traffic message communications, we propose an improved vehicular reputation system that manages the reputations of vehicles and verifies the reliability of traffic messages based on the vehicle reputation. We enhance our previously proposed community-based reputation model that an agent roadside unit (A-RSU) designated by a vehicle manages the reputation of the vehicle, and issues reputation certificates. In particular, we introduce practical ways of evaluating vehicle's reputation in real time and delivering the evaluated results to the A-RSU efficiently. The reputation of a vehicle is measured by the communication behaviors of the vehicle. All traffic event-based messages of the vehicle are evaluated by neighbors, and a local proof of the evaluation is delivered to the A-RSU. Finally, the A-RSU updates the reputation certificate of the vehicle based on the local proofs. We introduce an aggregated local proof generation mechanism based on the agreement of neighbors, and also provide efficient local proof delivery strategies. Our simulation results show that our proposed routing model outperforms in terms of average link duration, throughput and routing overheads than other routing strategies.