A Vehicle-to-Vehicle (V2V) communication system for smart cities is proposed here. The V2V communication system is an advance wireless technology to reduce the number of fatal roadway accidents by providing early warning messages. For development of smart cities V2V and V2R are important to reduce road accidents on highways. It gives ease of access by providing different facilities such as ATM transaction, accidents safety messages to the transport or central unit. Based on a careful analysis of application requirements, an effective protocol can be used, which comprising congestion control policies, service differentiation mechanisms and methods for emergency warning dissemination. The proposed protocol achieves low latency in delivering emergency warnings and use of efficient bandwidth in stressful road scenarios. This system uses WSN for communication between two vehicle modules.