How Can Vehicular Communication Reduce Rear-End Collision Probability on Highway

As a key component of intelligent transport system (ITS), vehicular communication network (VCN) is expected to reduce traffic accidents by providing more information to drivers via wireless communication. However, it remains unknown how VCN affects traffic accident probabilities. Given a highway scenario where vicious rear-end collision accidents happen, this paper investigates the impact of VCN on the rear-end collision probability. Considering a three-vehicle chain on highway and assuming that VCN conveys braking messages, vehicle behaviors are analyzed. Based on these analyses, the average collision probability of the concerned vehicle can be derived as a function of the communication success probability and driving parameters such as reaction time and deceleration. The analyses show that the average distance of adjacent vehicles is critical to reduce the probability of collision, especially when there is no VCN. When VCN is introduced, the collision probability could be reduced in two ways. One is that the reaction time of the vehicle is decreased and the other is that VCN could provide more information to the vehicle so that it can take precautions to avoid collision. Moreover, due to the relatively short distance of interest (i.e., less than 500 meters) and favorable wireless channel conditions on highway, the communication between vehicles always success and the collision probability with non-ideal communication can be reasonably approximated by that with ideal communication. These analytical results are verified by numerical computation and simulations. It is also shown that given a transmit power of 10dBm, aided by VCN, the rear-end collision probability of the concerned vehicle on highway can be significantly reduced by 70% compared to that without communications.