Vehicle-to-vehicle (V2V) communications play a critical role in enabling numerous important cooperative safety applications. V2V safety communications rely on broadcast of self-state information (e.g., position, speed, and heading) by each vehicle, which allows a vehicle to track its neighboring vehicles in real time. One of the most pressing challenges in this research is to maintain acceptable tracking accuracy of neighboring vehicles while avoiding congestion in the shared communication channel. In this article we describe the evaluation of a transmission control protocol that adapts...