What Is Emergency Vehicle Preemption?
Emergency Vehicle Preemption (EVP) allows authorized vehicles to briefly take control of traffic signals in their path, stopping conflicting traffic and giving them a clear, predictable route through intersections when seconds matter.
Why Emergency Vehicle Preemption Is So Important
Statistics and real-world experience show that a significant share of responder injuries and fatalities occur in traffic crashes enroute. Intersections are especially dangerous: distracted drivers, heavy congestion, limited sightlines, and noise inside modern vehicles can all delay how quickly motorists react to lights and sirens.
EVP gives equipped intersections a way to actively help emergency vehicles: by identifying them in advance, stopping conflicting traffic, and providing a clear path through the signal. This protects the public and the responders themselves while helping reduce response times when seconds can change outcomes.
How EVP Works at a High Level
An EVP system equips both the emergency vehicle and the intersection. As the vehicle approaches:
- The vehicle unit reports its position, direction, and status.
- The cabinet unit at the intersection listens for authorized vehicles.
- The system determines when preemption should start based on distance and approach.
When preemption is active, the signal controller:
- Stops conflicting traffic movements as safely as possible.
- Serves the phase that provides a clear path for the emergency vehicle.
- Holds that movement until the vehicle has cleared the intersection.
Once the event ends, the controller transitions back to normal operation using timing and rules set by the traffic engineering team.
Where the ELiMiNATOR® Fits In
The ELiMiNATOR® is a GPS and 900 MHz radio-based EVP and collision avoidance system designed specifically for real-world conditions: congested corridors, complex intersections, and today’s distracted driving environment.
By combining long-range radio with GPS, the ELiMiNATOR® helps intersections see authorized emergency vehicles sooner, coordinate safe preemption, and generate logs that support safety analysis, reporting, and smart city initiatives.