Which device is activated by flashing emergency lights to turn the traffic signal green for the emergency vehicle?

Which device is activated by flashing emergency lights to turn the traffic signal green for the emergency vehicle?

• A. Strobe light preemption device
• B. Traffic signal preemption device
• C. Manual control device
• D. Audible preemption device

Answer: (A)

The system being tested is about giving emergency vehicles priority at intersections through preemption. When an emergency vehicle equipped with the proper signaling uses its flashing lights, a strobe light preemption device on the vehicle communicates with the intersection’s preemption receiver. That signal tells the traffic signal controller to override its normal timing and switch the approaching lane to green, allowing the emergency vehicle to pass quickly and safely. This specific device is designed to respond to those flashing lights and initiate the green phase, distinguishing it from manual controls (which require human input) or audible preemption (which uses sound signals) or a broader term that could refer to other parts of the system.

The system being tested is about giving emergency vehicles priority at intersections through preemption. When an emergency vehicle equipped with the proper signaling uses its flashing lights, a strobe light preemption device on the vehicle communicates with the intersection’s preemption receiver. That signal tells the traffic signal controller to override its normal timing and switch the approaching lane to green, allowing the emergency vehicle to pass quickly and safely. This specific device is designed to respond to those flashing lights and initiate the green phase, distinguishing it from manual controls (which require human input) or audible preemption (which uses sound signals) or a broader term that could refer to other parts of the system.