RADAR TRAILER These mobile devices display the drivers travel speed on a large display along with the posted speed limit. Their goal is to encourage compliance. Their effectiveness tends to be limited to the times when they are displayed - with minimal effect on speed when they are removed. A drop in speed of 25 percent is possible with the devices when displayed. After a series of applications an overall drop in speed of about 6 percent has been found when traffic volumes are less than 600 vehicles per day. On higher volume streets their impact has been found to be negligible. Temporary Installation Permanent Installation Source: 3m.com PROS 1. This tool can be effective when displayed and may improve effectiveness with multiple applications on lower volume streets (<600 vpd). 2. May be popular with residents. 3. Low cost measure. 4. Can be used with Speed Alert Program. 5. Easily deployed. CONS 1. Minimal effectiveness when device is removed. 2. Minimal long-term impact on travel speeds. 3. Requires staff time to & from location to location. 4. Subject to vandalism. Summary of Effectiveness Volume Reduction No Speed Reduction Yes Safety Improvement Unknown - - Streets to Use On Collector, Local Local/Collector Use on Bus Route Yes Use with Curbs and Gutters Yes Spot or Area-wide Use Spot - - Emergency Service Access Issues No Impacts on Arterials Unlikely Change in % Trucks Unknown Environmental Changes No - - Dependence on Enforcement No Level of Violation Low - - Aesthetics and Landscaping No

Back to Toolbox