Evaluation of Retroreflective Material on Stop Sign Posts in Virginia

About the report:

The 2003 Manual on Uniform Traffic Control Devices (MUTCD) provides departments of transportation (DOTs) the option of using retroreflective material on sign posts when the DOTs determine that there is a need to draw attention to the sign, especially at night.  The MUTCD also provides standards for the design of these materials on the posts.  The material must be at least 2 inches wide and must be placed the full length of the post from the sign to within 2 feet above the edge of the roadway.  In addition, the color of the material must match the background color of the sign except that the color of the strip for “yield” and “do not enter” signs must be red.

 In response to receiving information about states that use retroreflective material on signposts, Senator George L. Barker introduced Senate Joint Resolution (SJR) 119, co-sponsored with Senator Kenneth T. Cuccinelli, in the Virginia General Assembly.  SJR 119 directed that the Virginia Department of Transportation (VDOT) study the feasibility, costs, and benefits of applying retroreflective material to stop signposts statewide.  The original bill was amended to add yield signs.  Although the bill did not pass, the Virginia Transportation Research Council agreed to conduct this study, limiting the scope to stop signs. 

The purpose of this study was to evaluate the effectiveness of retroreflective material on stop signposts in Virginia with respect to visibility and driver compliance at the stop sign.  The investigation included a review of the feasibility, costs, and benefits of this application.  In addition, a review of practices by other localities and DOTs was performed and field studies were conducted to examine visibility and driver compliance. 

 Key findings included: 

• Very few state DOTs apply retroreflective panels on stop signs.
• A video-based survey revealed that stop signposts without the retroreflective panels are detected earlier and seen more clearly during the day than posts with the panels.  Conversely, stop signposts with the retroreflective panels are detected earlier and seen more clearly at night than stop signposts without the panels.
• There is no difference in driver compliance for a stop sign with or without a retroreflective panel during the day or night.
• Retroreflective panels have only a minor impact on mean vehicle speeds as vehicles approach stop signs.
• The cost of adding and maintaining retroreflective panels on stop signs statewide is estimated at $1.186 million annually.

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