Safety Evaluation of Improved Curve Delineation

This TechBrief is a technical summary of the Federal Highway Administration report, "Safety Evaluation of Improved Curve Delineation" (FHWA-HRT-09-045). The objective of this study was to evaluate the safety effectiveness of improved delineation on horizontal curves through signing improvements. The study examined the effects of this strategy on specific non-intersection crash types including total, injury and fatal, lane departure, total during dark, and lane departure during dark in a rigorous crash-based analysis. The general conclusion from this research is that delineation improvements for curves have the potential to reduce crashes and crash severity on two-lane rural roads. Based on the installations in Connecticut and Washington, the combined results indicate substantial and highly significant crash reductions— injury and fatal (18%), dark conditions (27.5%), and dark condition lane departure (25.4%). In Connecticut, the effectiveness was greater for curves where more signs were either added or replaced within the curve. An economic analysis revealed that improving curve delineation with signing improvements is a very cost-effective treatment with the benefit-cost ratio exceeding 8:1. Given the potential to reduce crashes, the use of curve delineation improvements is justified as a safety improvement, particularly at curves with more hazardous roadsides, higher traffic volumes, and smaller curve radii.


  • English

Media Info

  • Media Type: Web
  • Features: Figures; Photos; References; Tables;
  • Pagination: 8p
  • Serial:
    • TechBrief
    • Issue Number: FHWA-HRT-09-046
    • Publisher: Federal Highway Administration
  • Publication flags:

    Open Access (libre)

Subject/Index Terms

Filing Info

  • Accession Number: 01139589
  • Record Type: Publication
  • Report/Paper Numbers: FHWA-HRT-09-046, FHWA-HRT-10-019 (Revised Oct 2009)
  • Files: NTL, TRIS
  • Created Date: Sep 17 2009 2:00PM