Incorporating Road Safety into Pavement Management: Maximizing Surface Friction for Road Safety Improvements

Available Documents
Quarterly Report October 2003
Quarterly Report Mar 2004
Quarterly Report Sept 2004
Quarterly Report Dec 2004
Quarterly Report March 2005
Quarterly Report June 2005
Quarterly Report September 2005
Quarterly Report December 2005
Quarterly Report March 2006
Quarterly Report June 2006
Quarterly Report September 2006
Quarterly Report December 2006
Quarterly Report March 2007
Draft Literature Review and State Surveys
Final Report

Primary Investigator
David A. Noyce, Ph.D., P.E.
Hussain U. Bahia, Ph.D.
University of Wisconsin – Madison

Project Objective
The objective of this research is to integrate road safety and pavement management strategies. Specifically, objectives include:

  1. Determine the relationship between skid resistance and traffic safety;
  2. Develop asphalt pavement mix design strategies that consider skid resistance as its primary measure of effectiveness;
  3. Identify existing prediction models for skid resistance, propose modifications to models, and identify minimum skid resistance ranges to trigger the need for roadway maintenance;
  4. Incorporate skid resistance and safety in a pavement asset management tool.

Project Abstract
Traffic crashes and the associated injuries and fatalities continue to be a significant problem for transportation professionals. In 2001, 37,795 motor vehicle fatalities were
reported in the United States as a result of over 6.3 million crashes (1). Over one-third of these crashes included personal injury to at least one of the vehicle occupants. The Region 5 states accounted for 6,360 of the 42,116 transportation fatalities in 2001, approximately 15 percent of the national total. Although numerous safety measures have been implemented in recent years, ranging from stricter safety laws and public awareness campaigns to roadway and traffic control device improvements, total crashes and fatalities per year continue at unacceptable rates. Little has been done to incorporate safety into the pavement management and maintenance decisions that are made. Nevertheless, the results of numerous road crash investigations and statistical analysis have suggested that there is a relationship between crash frequency and pavement surface conditions. This relationship is not well understood.

A vehicle that has lost contact with the pavement and entered a skidding maneuver is a safety hazard to drivers. High pavement skid resistance properties resulting in minimized skid lengths can be significant in reducing or eliminating the magnitude of a crash impact. Skid resistance can also be significant is keeping vehicles on the roadway during aggressive horizontal and lateral movements. The method used today for measuring resistance to skidding is measuring the friction provided by the surface to a typical tire traveling at a specified speed, under selected climatic and surface wetting conditions. There is a fair [j1]amount of variability within the specifics of these methods. It is well recognized that skidding is a phenomenon related to both the tire and surface
characteristics. Normal load (weight), tire tread, temperature, and water all affect skidding. Thus it is essential to use standardized tires and conditions to compare resistance offered by surfaces to skidding.

Task Descriptions
The measures used for skid will be analyzed. The experience of Wisconsin will be analyzed. The relationship between safety and skid numbers will be analyzed and therelationship between specific materials and skid will be analyzed. Guidelines will be developed for the use of materials in maintenance activities to reduce the impact ofskid.

Relationship to Other Research Projects
None.

Technology Transfer Activities
Guidelines will be established and included in a final report.

Potential Benefits of the Project
The project could provide valuable insights into one of the contributing factors of highway crashes.

Project Information

  • Milestones, Dates: Project Start Date: June 1, 2003. Project End Date: May 31, 2005
  • Budget: $157,798 (REVISED 8/2003: $234,428)
  • Student Involvement: 2 graduate students
  • TRB Keywords: Skid Resistance, Traffic Safety, Asset Management
  • Primary Subject: Integration of Road Safety and Pavement Management
  • Modal Orientation: Highway
  • Project Number: 04-04