Using freeway traffic data to estimate the effectiveness of rear-end collision countermeasures

TLDR: Applications of the model indicate that a collision warning system with a range of about 250 feet has the potential to reduce the number of all rear-end collisions by 50 percent and the more serious ones by over 60 percent.

Abstract: This paper describes a model for (1) studying the genesis of rear-end collisions in freeway traffic and (2) estimating the potential benefits of collision warning systems in such crashes. The model is known as REAMACS (Rear-End Accident Model and Countermeasure Simulation). REAMACS uses a quasi-Monte Carlo routine to generate the initial conditions that determine whether or not a crash occurs. Applications of the model indicate that a collision warning system with a range of about 250 feet has the potential to reduce the number of all rear-end collisions by 50 percent and the more serious ones by over 60 percent. Further, the impacts speeds of crashes that do occur are reduced by a 250-foot range system by as much as 38 percent.