Transit Vehicle Signal Priority & Emergency Vehicle Preemption

Traffic signals equipped with technology to prioritize transit vehicles and allow emergency vehicles to request preemption at intersections and bypass stopped vehicles or congestion.

Page updated on Jul 6, 2021 at 3:09 PM

What is Signal Priority?

Transit Signal Priority (TSP) and Emergency Vehicle Pre-emption (EVP) allows vehicles such as buses, fire trucks and other emergency vehicles to get through traffic signals quicker.  These vehicles talk directly to the traffic signal to alert the signal that they are approaching. The signal will either stay green longer, or if it is red, shorten the red light. The goal is to keep buses on schedule and improve travel times for emergency vehicles.  Improving the on-time performance of buses increases reliability and makes the bus a more attractive option and reducing time emergency vehicles are stuck in traffic improves health outcomes.  

What's New?

The City completed TSP projects along Duke Street this spring and EVP was installed at Quaker Lane and Seminary Road.

Project Background

TSP is a regional initiative that began in 2010 with the goal of provided consistent TSP that WMATA buses could use to operate in all the regional jurisdictions.   The system was expanded, and the DASH fleet was equipped so their buses can also use the TSP system in Alexandria.  The City was awarded grant funding for this project that totals over $2.1 million, and DASH was awarded $2.1 million in FY24 to continue to outfit their fleet and expand TSP corridors.  TSP and EVP has already been deployed on parts of Seminary Road, Duke Street, Van Dorn Street and Beauregard Street.  A project to install TSP & EVP on King Street and the remainder of Duke Street is underway and expected to be complete in the fall of 2020.

Transit Signal Priority Corridors