Most communities rate benefits of emergency vehicle traffic signal pre-emption from “moderate” to “very high”.

Nine communities utilizing emergency vehicle traffic signal pre-emption.

Date Posted

Best Practices in Traffic Incident Management

Summary Information

In 2010, the Federal Highway Administration (FHWA) published a handbook of best practices for overcoming common challenges in traffic incident management (TIM). These practices can help improve TIM nationally by sharing information on the tools and strategies found to be effective. The FHWA developed the best practices with information from publications and input from practitioners in incident response, including experts from law enforcement, fire and rescue, emergency medical services, transportation, and towing and recovery agencies representing perspectives from 14 states.

Traffic signal pre-emption systems allow a temporary interruption to normal operation of traffic signals to give emergency vehicles priority. This is done by changing traffic signals in the path of the vehicle to green and stopping conflicting traffic.


In this investigation, TIM personnel in Redding, CA, Windsor, CA, Baltimore, MD, Henderson, NV, New York, NY, Austin, TX, and Bellevue, WA rated the benefits of traffic signal pre-emption as "moderate" to "very high" in effectively enhancing access of emergency vehicles to incident scenes.

Traffic signal pre-emption was rated as "very low" to "low" in enhancing scene access by TIM personnel in Salt Lake City, UT and the Delaware Valley region in NJ and PA.

The range in reported effectiveness may partially be explained by the number of intersections equipped with traffic signal pre-emption and effort expended in maintaining the system to ensure ongoing functionality.
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