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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation
FHWA Highway Safety Programs

Retroreflective Borders on Traffic Signal Backplates

Publication Year:

Original publication: Retroreflective Borders on Traffic Signal Backplates – A South Carolina Success Story; FHWA-SA-09-011; 2009 (PDF, 377kB)

Red-light running is estimated to cause more than 200,000 crashes, 170,000 injuries, and approximately 900 deaths per year (Source: Federal Highway Administration, Red-Light Running Web Site (2008)). One of the reasons for the high number of crashes is driver inability or failure to see the traffic control device in time to comply. The South Carolina DOT (SCDOT) was concerned about the high number of crashes at some of its urban signalized intersections. It recognized that poor signal visibility can cause crashes. In response, SCDOT installed retroreflective borders on existing signal backplates at three intersections in the Columbia area that were experiencing a high incidence of crashes, many with injuries.

"Closeup photograph of a retroreflective traffic light, showing the signal backplate and the retroreflective border applied to the perimeter of the backplate"
Figure 1   Photo courtesy of KLS (used with permission)

 

"Photograph of a set of three retroreflective traffic lights across a pole during daylight and another photograph of a different set of three in darkness"
Figure 2   Photos courtesy of South Carolina Department of Transportation (used with permission)

 

Key Accomplishments

The SCDOT experience demonstrates that low-cost improvements can effectively improve safety and reduce traffic crashes and their resulting injuries.

Results

The retroreflective borders installed at these Columbia signalized intersections cumulatively reduced total crashes by approximately 28.6 percent, injury crashes by 36.7 percent, and late-night/early morning crashes by 49.6 percent per year.

Contact

Joey D. Riddle
SCDOT
RiddleJD@dot.state.sc.us