U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
Enhanced delineation at horizontal curves includes a variety of potential strategies that can be implemented in advance of or within curves, in combination, or individually.
|Potential Strategies||In advance
(standard width or wider)
|In-lane curve warning pavement markings||X|
|Retroreflective strips on sign posts||X||X|
(larger, fluorescent, and/or retroreflective signs)
|Dynamic curve warning signs
(including speed radar feedback signs)
|Sequential dynamic chevrons||X|
Enhanced delineation treatments can alert drivers to upcoming curves, the direction and sharpness of the curve, and appropriate operating speed.
Agencies can take the following steps to implement enhanced delineation strategies:
1. Albin et al. Low-Cost Treatments for Horizontal Curve Safety 2016. FHWA-SA-15-084, (2016).
2. Srinivasan et al. Safety Evaluation of Improved Curve Delineation. FHWA-HRT-09-045, (2009).
3. Lyon et al. Safety Evaluation of Two Curve Warning Treatments: In-Lane Curve Warning Pavement Markings and Oversized Chevron Signs. Presented at the 96th TRB Annual Meeting, Paper No. 17-00432, (2017).
4. Hallmark, S. Evaluation of Sequential Dynamic Chevrons on Rural Two-lane Highways. FHWA, (2017).
5. Donnell et al. Reducing Roadway Departure Crashes at Horizontal Curve Sections on Two-lane Rural Highways. FHWA-SA-19-005, (2019).
Note: With the 2021 update of the PSCi, HFST is now included in Pavement Friction Management.
Filter countermeasures by focus area, crash type, problem identified, and area type.