The National Academies

NCHRP Synthesis 20-05/Topic 48-01 [Active (Synthesis)]

Practices for Preventing Roadway Departure Crashes
[ NCHRP 20-05 (Synthesis of Information Related to Highway Practices) ]

  Project Data
Funds: $45,000
Authorization to Begin Work: 5/9/2016 -- estimated
Staff Responsibility: Jo Allen Gause
Research Agency: Independent Consultant
Principal Investigator: Hugh McGee
Effective Date: 9/8/2016
Fiscal Year: 2016

Final Scope

A roadway departure (RwD) crash is defined by the Federal Highway Administration (FHWA) as “A crash which occurs after a vehicle crosses an edge line, a centerline, or otherwise leaves the traveled way.” The reasons for RwD events are varied and include inattentive driving due to distraction, fatigue, sleep, or intoxication; the effect of weather on pavement conditions; and traveling too fast through a curve or down a grade. According to seven years of crash data (2007-2013) from the Fatality Analysis Reporting System (FARS) database, an average of 57 percent of motor vehicle traffic fatalities occurred each year due to RwD in the United States.

Different engineering countermeasures have been implemented by various state and local agencies to mitigate RwD crashes. These countermeasures are targeted toward the following three risk categories: keeping vehicles on the roadway; minimizing the consequences of leaving the roadway; and reducing head-on and cross-median crashes. Countermeasures have been used in all area types (i.e., rural, suburban, and urban) to keep vehicles in travel lanes and to reduce potential collisions with roadside objects, such as trees, signs, and utility poles.

The objective of this synthesis is to document and summarize countermeasures to prevent
RwD crashes and their data-driven advantages and/or disadvantages. The synthesis will focus on enhancements, treatments, and improvements of existing roads.

Information to be gathered includes (but is not limited to):
• Countermeasures organized by the three risk categories mentioned above;
• Relative extent of use (e.g., rarely, moderately, widely);
• Conventional and innovative countermeasures;
• Implementation hurdles that were overcome (e.g. policy, maintenance, public feedback);
• Programmatic implementation strategies (e.g., hot spots versus systemic); and
• Agency countermeasure evaluations (e.g., before and after safety analysis, CMF and/or SPF, durability studies, life cycle cost analysis)

Information will be gathered by literature review, a survey of state DOTs, and follow-up interviews with selected agencies. Surveys should be directed voting members of the AASHTO Subcommittee on Safety Management.

Information Sources (Partial):
• NCHRP Report 500, Vol. 20, A Guide for Reducing Head-On Crashes on Freeways
• NCHRP Report 500, Vol. 8: A Guide for Reducing Collisions Involving Utility Poles
• NCHRP Report 500, Vol. 3: A Guide for Addressing Collisions with Trees in Hazardous Locations
• NCHRP Report 500, Vol. 6: A Guide for Addressing Run-Off-Road Collisions
• NCHRP Report 500, Vol. 7: A Guide for Reducing Collisions on Horizontal Curves
• Washington State Department of Transportation safety evaluation analysis of chevron signs for 139 treated curves on rural two-lane roads
• Kentucky Transportation Cabinet (KYTC); 2006 installation of an LED-enhanced curve warning sign on KY 82 in Estill County
• KYTC; 2010 launch of 3-year high friction surface treatments program to enhance friction for horizontal curves at 75 locations
• Mobile County AL; 2010 implementation of a systematic application of raised pavement markers along 10 rural roadways with the highest number of RwD crashes
• Missouri Department of Transportation; 2009-2012 program installation of edge line marking on eligible High Risk Rural Roads
• Minnesota Department of Transportation; 2004-2008 installation of cable barriers at 31 segments along approximately 150 miles of freeways to reduce the number of fatalities and severe injuries caused by cross-median crashes
• Iowa Department of Transportation; 2006 program to mitigate RwD crashes focusing on removal/relocation of hazards (e.g., trees, telephone poles, mailboxes) within the clear zone area and shielding or delineating objects) 

TRB Staff
Jo Allen Gause
Phone: 202-334-3826
Email: jagause@nas.edu

Meeting Dates
First Panel:  September 8, 2016, Washington, DC
Teleconference with Consultant: October 3, 2016, 10:00 a.m., EST
Second Panel: June 22, 2017, Washington, DC

Topic Panel
Ronald K. Faller, University of Nebraska - Lincoln
Donna Hardy, West Virginia DOT
Tracy A. Lovell, Kentucky Transportation Cabinet
Stephen W. Read, Virginia DOT
Rebecca Y. Szymkowski, Wisconsin DOT
Brian J. Walsh, Washington State DOT
Adam S. Weiser, Delaware DOT
Eduardo Arispe, Federal Highway Administration
Frank C. Julian, Jr., Federal Highway Administration
Stephen F. Maher, Transportation Research Board


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