Pavement Friction

Roadway departure crashes account for the majority of roadway fatalities, and many of them occur on wet pavements. 

70 % of wet pavement crashes can be prevented or minimized by improving pavement friction.

Background

In 2008, more than 19,000 people were killed in roadway departure crashes in the 

United States. Poor roadway conditions, especially wet pavement, has been

identifi ed as a major contributing factor in roadway departure crashes.

Current Federal Highway Administration (FHWA) policies regarding pavement are 

as follows:

 The FHWA pavement policy indicates that States shall design pavement to 

accommodate current and predicted traffi c needs in a safe, durable, and cost 

eff ective manner. 

 The FHWA policy related to the Highway Safety Improvement Program (HSIP) 

indicates that each State shall incorporate a process for analyzing available 

safety data that identifi es highway safety improvement projects on the basis of 

crash experience, crash potential, or other data supported means.

Further, research conducted by the National Transportation Safety Board and 

FHWA indicates that about 70% of wet pavement crashes can be prevented or minimized by improved pavement friction.

New FHWA Guidance on Pavement Friction Management

A new technical advisory issued by FHWA on June 17, 2010, Pavement Friction Management (T 5040.38), provides

guidance to State and local highway agencies on managing pavement surface friction on roadways. The new advisory 

supersedes the 1980 FHWA Technical Advisory 5040.17, Skid Accident Reduction Program.

The new technical advisory also covers topics such as: test equipment for measuring pavement friction; the identifi cation 

and classifi cation of roadway locations with elevated crash rates; how to prioritize projects for improving pavement friction; the appropriate frequency and extent of friction testing on a highway network; and how to determine a pavement 

friction management program’s eff ectiveness. Additional reference materials on pavement friction management and 

measurement are highlighted as well.

Purpose of a Friction Management Program

The main purpose of a pavement friction management program is to minimize friction-related vehicle crashes by:

 Ensuring that new pavement surfaces are designed, constructed, and maintained to provide adequate and durable

friction properties;

 Identifying and correcting sections of roadways that have elevated friction-related crash rates; and

 Prioritizing the use of resources to reduce friction-related vehicle crashes in a cost-eff ective manner.

1. 70% of wet pavement crashes 

can be aff ected by pavement 

friction improvements.

2. States should do the following:

a. Establish a Pavement Friction 

Management Program.

b. Develop policies to improve 

new pavement friction.

c. Address locations with 

immediate safety needs with 

high-friction overlays.

Key Points
U.S. Department of Transportation

Federal Highway Administration

Key Components of a Friction Management Program

Pavement friction management includes engineering practices to provide 

surfaces with adequate and durable friction properties plus data collection 

and analysis to ensure the eff ectiveness of the engineering practices. The 

most eff ective data collection and analysis components of friction management programs use pavement friction and friction-related data, crash data, 

and traffi c data to:

 Evaluate pavement design, construction, and maintenance practices to 

ensure pavement surfaces with good friction characteristics are provided; 

 Identify and investigate locations with elevated wet-weather crash rates 

relative to comparable locations for the purposes of minimizing

locations with elevated friction-related crash rates; and

 Provide data for use in prioritizing projects to improve highway safety.

Pavement Friction Program Examples

The New York State DOT (NYSDOT) implemented a program to identify sites statewide with a low skid resistance and 

treat them with overlays as part of their maintenance program. A site is eligible for treatment if its 2-year wet accident 

proportion is 50 % higher than the average wet crash proportion for roads in the same county. Between 1995 and 1997, 

NYSDOT treated 36 sites, which reduced the annually recurring wet road crashes by more than 800. These results, and 

others throughout the State, support earlier fi ndings that treating wet-road crash locations can reduce this type of crash 

by 50% and reduce total crashes by 20%. 

The Florida DOT (FDOT) treated a curved freeway ramp with Tyregrip®, a high-friction material consisting of a highly modifi ed exothermic epoxy resin dressed with a calcinated bauxite with a Polish Stone Value of 70%+. This treatment proved 

eff ective at increasing the skid resistance value from 35 to 104. While the FDOT application was on a freeway ramp, the 

material may also be applicable to a higher volume curve with a higher than normal number of wet pavement crashes. 

The treatment type and product example provided above does not imply validation or endorsement by the FHWA Offi ce 

of Safety; several products and materials are available and should be considered to improve pavement friction.

For More Information

FHWA’s Pavement Friction Management Technical Advisory at www.fhwa.dot.gov/pavement/t504038.cfm

Guide for Pavement Friction NCHRP Project 1-43 at http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rrd_321.pdf

Evaluation of Pavement Friction Characteristics NCHRP SYNTHESIS 291 at

 http://pubsindex.trb.org/view.aspx?id=675639

Mark Swanlund

FHWA Offi ce of Infrastructure

202-366-1323

mark.swanlund@dot.gov

http://safety.fhwa.dot.gov/index.cfm

Source: FHWA

Joseph Cheung

FHWA Offi ce of Safety

202-366-6994

joseph.cheung@dot.gov