Surprise adopts GPS-based system to trigger green lights for emergency vehicles

City of Surprise officials on Jan. 21 presented an update on a newly deployed GPS-based emergency vehicle traffic signal preemption system intended to give responding apparatus earlier green lights and reduce hazardous stops at intersections.

The system uses GPS-equipped routers in fire medical vehicles to share location and a wired input that senses when lights-and-sirens are active; when the device detects a responding unit inside a configurable geofence, the central server sends commands to one or multiple intersections to prepare or grant a green phase. "It has geofences placed throughout the city on the roadways," said Albert Garcia, the city's TISMO manager in the Transportation Department. "They can be polygon shapes that go around corners that sit in driveways of the fire stations."

Why it matters: Fire officials told the council the existing infrared optical preemption system works in many situations but is limited by line-of-sight, range and long pedestrian timings at large intersections. Battalion Chief Cody Worrell said those constraints can force crews to stop at signals and visually clear multiple lanes, increasing the risk of secondary…