Speed feedbackUnited States

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44. Speed feedback

Speed feedback is a traffic-safety system that measures an approaching vehicle's speed and displays it back to the driver. The display may show the measured speed together with a message, colour or symbol indicating whether the vehicle is travelling within the applicable speed limit.

Speed feedback displays are intended primarily to make drivers aware of their speed and encourage them to slow down when necessary. They normally serve a preventive or educational purpose rather than establishing a new speed limit.

Speed feedback
25 mph speed-limit and speed-feedback signs on Maryland Route 281 at Big Elk Creek. (Elkton, Maryland, United States)
Wikimedia.org • Famartin • CC BY-SA
What is a speed feedback display?

A speed feedback display is an electronic roadside device that measures an approaching vehicle's speed and shows that speed to the driver.

Why are speed feedback displays used?

They are used to increase drivers' awareness of their actual speed and encourage compliance with the applicable speed limit.

Does a speed feedback display set the speed limit?

Normally, no. The legally applicable speed is determined by the traffic rules and regulatory speed-limit signs, while the feedback display simply informs the driver of their measured speed.

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