Simple Worksheet Method to Evaluate Emergency Vehicle Preemption and Its Impacts on Safety

Abstract

Providing safe and efficient public safety services is a primary function and obligation of local governments. Rapid growth and congestion coupled with the increasing need to provide safe and efficient arterial access to first responders have challenged public officials seeking to make budget decisions that support higher levels of fire and rescue service quality. Emergency vehicles (EVs) operating in higher congestion levels are at risk for involvement in crashes and delays in reaching the scene of a fire or accident. One means to offset the effects of congestion is installation of emergency vehicle preemption (EVP) equipment at signalized intersections. This intelligent transportation system technology provides a special green interval to the EV approach while providing a special red interval on all conflicting approaches. The effects of EVP are a reduction in exposure to active conflict points, thereby reducing crash potential, and dispersion of the queues, thereby allowing the EV to maintain higher average operating speeds along the response route. The problem faced by local policy makers and by transportation and public safety officials is that there are no national guidelines or methods to aid in the evaluation of intersections and corridors under consideration for EVP deployment. One element of this issue is addressed: the need for a method to evaluate the safety benefits of EVP for one intersection or corridor over another in relative terms. It proposes a simple tool, usable in safety audits and engineering studies, to determine which intersections or corridors would benefit most from EVP.