How Effective Are Radar Speed Signs?

Radar speed signs have been proven to be highly effective in calming traffic and reducing the likelihood of fatal accidents involving pedestrians and automobiles. Studies consistently show that slowing down traffic significantly decreases the chances of severe outcomes. For instance, a pedestrian struck by a car at 40 mph faces a staggering 90% fatality rate, whereas at 20 mph, the fatality rate drops drastically to just 10%. The accompanying graph underscores the profound impact that even a minor reduction in speed can have on the survival outcomes for those involved in such incidents.

Fatality rate for pedestrians hit by vehicles at different speeds

Radar speed signs stand as a tried-and-true solution for promoting speed awareness among drivers. Studies consistently highlight their efficacy, revealing that drivers, when alerted by a radar sign, exhibit a substantial reduction in speed up to 80% of the time. On average, radar signs contribute to typical speed reductions ranging from 10% to 20%, leading to an impressive overall compliance increase of 30-60% with posted speed limits. Radar signs are particularly effective at getting “super speeders”—speeders driving 20 mph or more over the posted speed limit—to slow down..

All data collected with StreetSmart Traffic Data Collection and Reporting software.

Decline in Average Speeds

After 21 months of operation, the radar speed sign continues to be effective
in reducing the average speeds in a 25 MPH neighborhood cut-through street.

Average Vehicle Speeds: By MPH Segments
Raising Speed Awareness  with Radar Speed Signs -sample data report

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Shift of Peak Speeds to Lower Speeds

Six months of operation of a radar speed sign on a neighborhood cut through street demonstrates the effectiveness of the sign in lowering peak speeds to lower speeds.

Peak Speed Shifts: By MPH Segments
Raising Speed Awareness  with Radar Speed Signs -sample data report

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Speed Limit Compliance At Plant Entrance

1.5 years of radar speed sign operation at a plant entrance shows 55% more vehicles obeying the posted speed limit (PSL).

Radar Sign Reduces Speeding At Plant By 55%!
Raising Speed Awareness  with Radar Speed Signs -sample data report

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Long Term Reduction In Speeding Drivers

2 years of radar speed sign operation on a 40 MPH arterial street shows consistent, long-term reduction of speed.

Percent of Vehicles Speeding
Raising Speed Awareness  with Radar Speed Signs -sample data report

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Long Term Reduction In Average Speeds

2 years of radar sign operation on a 40 MPH arterial street shows average speeds maintain drop of 3.5 MPH.

Weekly Average Speeds
sample data report

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