1. Report No.

FHWA-SA-03-002

4. Title and Subtitle

Workshops on Nighttime Visibility of Traffic Signs: Summary of Workshop Findings

5.Report Date

February 2003

6. Performing Organization Code

7. Author(s)

H. Gene Hawkins, Paul J. Carlson, Greg F. Schertz, and Kenneth S. Opiela

9. Performing Organization Name and Address

Texas Transportation Institute
3135 TAMU
College Station, TX 77843-3135

under contract to:

Battelle
505 King Avenue
Columbus, Ohio 43201-2693

11. Contract or Grant No.

DTFH61-01-C-00182/

WO BA82B005

12.Sponsoring Agency Name and Address

Federal Highway Administration
Office of Safety
400 7th Street, SW
Washington, D.C. 20590

13.Type of Report and Period Covered

15. Supplementary Notes

Workshops conducted under subcontract to Battelle as part of a contract with the U.S. Department of Transportation, Federal Highway Administration.

Project COTR: Peter J. Hatzi

Federal Highway Administration (HSA-10)

16. Abstract

In the summer of 2002, the FHWA sponsored a series of workshops on minimum levels of in-service retroreflectivity for signs. These workshops were conducted to present the most recent research findings on minimum levels of retroreflectivity and to solicit input from public agency officials prior to developing a proposed rule on minimum levels of retroreflectivity. A total of 99 individuals participated in the four invitation-only workshops. Each workshop consisted of two half-days of presentations, with a nighttime sign visibility demonstration on the evening between the two days. The first half-day of the workshop was devoted primarily to presenting information on retroreflectivity concepts, recent updates to the minimum retroreflectivity levels, and a description of potential options for implementing minimum retroreflectivity levels. In the nighttime sign demonstration, the participants rated several signs with a range of retroreflectivity values. The second day of the workshop was primarily devoted to a discussion of the various issues and the development of recommended language for the MUTCD relative to minimum levels of sign retroreflectivity or visibility. Among the key findings of the workshops are that the public agency participants want the MUTCD to provide several methods that can be used to meet the minimum retroreflectivity guidelines and that numeric retroreflectivity values should not be included in the MUTCD.

17. Key Words

Traffic signs, retroreflectivity

18. Distribution Statement

No restrictions. This document is available to the public through NTIS:

National Technical Information Service
5285 Port Royal Road
Springfield, Virginia 22161

19. Security Classif. (of this report)

Unclassified

20. Security Classif. (of this page)

Unclassified

21. No. of Pages

108

22. Price