FHWA: Making Our Roads Safer One Countermeasure at a Time

http://safety.fhwa.dot.gov https://safety.fhwa.dot.gov/ provencountermeasures. 1. Enhanced Delineation and Friction for Horizontal Curves ROADWAY DEPARTURE | PROVEN SAFETY COUNTERMEASURES This proven safety countermeasure for reducing crashes at curves includes a variety of potential strategies that can be implemented in combination or individually. These strategies fall into two categories: enhanced delineation and increased pavement friction. Enhanced Delineation Increased Pavement Friction Chevron signs installed along a curve. Enhanced delineation treatments can alert drivers in advance of the curve and vary by the severity of the curvature and operating speed. Price ranges for these strategies are low to moderate. Treatments include the following: ƒ Pavement markings. ƒ Post-mounted delineation. ƒ Larger signs and signs with enhanced retroreflectivity. ƒ Dynamic advance curve warning signs and sequential curve signs. High friction surface treatment (HFST) is another highly cost-efective countermeasure. HFST compensates for the high friction demand at curves where the available pavement friction is not adequate to support operating speeds due to one or more of the following situations: ƒ Sharp curves. ƒ Inadequate cross-slope design. ƒ Wet conditions. ƒ Polished roadway surfaces. ƒ Driving speeds in excess of the curve advisory speed. Source: Thinkstock SAFETY BENEFITS: CHEVRONSIGNS 25% Reduction in nighttime crashes 16% Reduction in non-intersection fatal and injury crashes To implement these proven safety countermeasures, agencies can take the following steps: 1. Develop a process for identifying and treating problem curves. 2. Use the appropriate application for the identified problem(s), consider the full range of enhanced delineation and friction treatments. 3. Improve consistency in application of horizontal curve guidance provided in the Manual on UniformTrafic Control Devices for new and existing devices. 4. Review signing practices and policies to ensure they comply with the intent of the new guidance. Source: CMF Clearinghouse, CMF IDs 2438 and 2439 HIGHFRICTIONSURFACE TREATMENTS 52% Reduction inwet road crashes 24% Reduction in curve crashes Source: CMF Clearinghouse, CMF IDs 7900 and 7901