Highway chain collision avoidance using inter-vehicular communications

Statistics show that about 23% of all vehicle crashes per year are rear-end collisions. In most cases, these accidents are due to the sudden decrease in the speed of the front vehicle and insufficient time for the rear vehicles to decrease their speed. This is usually the consequence of limited view span of the driver and thus failure to react at the proper time. The issue exacerbates in today´s high-speed highways in which several fast-moving vehicles move consecutively in one line. In such situations sudden decrease in the speed of one vehicle may result in a chain collision. Due to limited coverage and functionality, current vehicle safety systems like sensor and radars fail to extend the view span of the drivers as desired. Therefore, recently taking advantage of vehicular short communications is attracting lots of interest among car manufactures and academic bodies. In this paper, we use the test-bed of the CVT-Project (Connected Vehicle Technology Project) to investigate the amount of success of inter-vehicle communications (based on IEEE 1609/WAVE standard) in chain collision avoidance. We first implement a multi-hop safety message dissemination algorithm through which approaching vehicles can be informed about sudden speed reductions (e.g., collisions) in a timely manner. In comparison to drivers´ perception which is simply based on brake-light of the front vehicle, the above-mentioned message dissemination buys some time for the drivers to react timely. Our results suggest that inter-vehicle communication technology contributes significantly in decreasing the probability of chain collision occurrence. Furthermore the number of vehicles involved in the accident is decreased noticeably. We also show that the severity of accident is reduced significantly by even 50% technology penetration.