Assessing the safety benefits due to coordination amongst vehicles during an emergency braking maneuver

In this paper, we consider the problem of estimating three safety parameters, namely, the probability of an intervehicular collision, expected number of such collisions and expected relative velocity at impact, for assessing the safety benefits of coordination. We consider an emergency braking scenario, in which the lead vehicle brakes at its maximum capability and the following vehicles obey a vehicle following control law. It is assumed that the maximum braking capability of all vehicles are independent and identically distributed random variable. The fact, that coordination renders effective braking of a vehicle different from its maximum braking capability, leads us to a natural way of analyzing the problem: the first step is that of determining how the coordination of vehicles alters the probability distribution of "effective" braking; this has been done in an earlier paper by the authors. The second step is that of determining how one can compute the probability of a collision, the expected number of primary collisions and relative velocity at impact in a platoon of n vehicles, from the knowledge of the probability distribution of "effective" braking and from the braking differential that guarantees a collision/no-collision between successive vehicles; this is the focus of this paper. We have conducted Monte Carlo simulation to demonstrate the safety benefits of coordination during emergency braking and the viability of our analytical approach to estimate them