Traffic Calming:

A Topic Not as Cut and Dried as You Might Expect

The classic questions we get all the time is "Are radar signs (trailers) effective at traffic calming?", "Don't they loose thier effectiveness over time?" and "Aren't all these makes pretty much the same?".

Now, us saying 'Yeah, sure they are!" or "No away!" isn't really meaningful. So let's hear it from the "authorities".

The Texas Transportation Institute at Texas A & M University with the assistance of Speed Measurement Labs has published two research studies, i.e., "Evaluation of Dynamic Speed Display Signs"-9)/2003, report #0-4475-I and "Evaluation of Speed Trailers At High Speed Temporary Work Zones”-1 /2000, report #00-1475. The reports found, "the average speed dropped substantially from 44.5 mph to 35.3 mph shortly after the sign was installed. Installing the signs resulted in a significant decrease in average speeds that was maintained over a 16 week period."

A University of Nebraska studied the short and long term effectiveness of radar displays; "Radar Speed Reporting Systems” March 2000. The sampling for this study exceeded 45,000 vehicles. This study concluded, "the Radar Display system was found to be effective in lowering speeds and increasing uniformity of speeds. Its effects increased speed limit compliance to 90% or more".