U.S Department of Transportation
National Highway Traffic Safety Administration

Technical Report Documentation Page

1. Report No.
DOT HS 809 530

2. Government Accession No.

3. Recipient’s Catalog No.


4. Title and Subtitle

5. Report Date

 Evaluation of the Repeal of Motorcycle Helmet Laws in Kentucky and Louisiana

 October 2003


6. Performing Organization Code


7. Author(s)

8. Performing Organization Report No.

R.G. Ulmer and D.F. Preusser


9. Performing Organization Name and Address

10. Work Unit No. (TRAIS)


Preusser Research Group, Inc.
7100 Main Street
Trumbull, CT 06611

11. Contract or Grant No.


12. Sponsoring Agency Name and Address

13. Type of Report and Period Covered

National Highway Traffic Safety Administration
Office of Research and Traffic Records
400 7th Street, S.W.
Washington, DC   20590

   Final Report


14. Sponsoring Agency Code


15. Supplementary Notes

Dr. Linda Cosgrove served as the NHTSA Contracting Officer's Technical Representative for the study. We appreciate the guidance and support she provided.

16. Abstract

    The 1998 universal motorcycle helmet law repeal in Kentucky and the 1999 repeal in Louisiana produced similar effects. Observed helmet use dropped from nearly full compliance under the laws to the 50 percent range without the laws. Motorcyclist fatalities increased in the near term by sizeable amounts-by over 50 percent in Kentucky and by 100 percent in Louisiana. Injuries also increased substantially in both states. At the same time, the number of registered motorcycles increased (by 20%), and vehicle miles traveled increased by approximately 6% (based on national numbers). Thus, some of the increase in fatalities in Kentucky and Louisiana were probably due to increased exposure.

In Kentucky, motorcyclists killed per 10,000 registered motorcycles averaged 6.4 in the two years just before the helmet law repeal and averaged 8.8 in the two years following its repeal, an increase of +37.5 percent. Persons injured per 10,000 registered motorcycles averaged 187 in the preceding two years and averaged 219 in the two years following its repeal, an increase of +17 percent. In Louisiana, the fatality rate averaged 4.5 in the two years prior to helmet law repeal and rose to 7.9 in the year following, an increase of +75 percent. The injury rate averaged 126 persons in the two years before the helmet law repeal and increased to 152 persons in the year following repeal of the universal motorcycle helmet law, an increase of +20.6 percent. For comparison purposes, the national fatality rate per 10,000 registered motorcycles increased 18% and injuries declined by 2.9%.

The experience in Kentucky and Louisiana is similar to the experience in Arkansas and Texas, two other states that repealed universal laws in recently (1997). This leaves little doubt that such repeals have demonstrable negative safety consequences.

17. Key Words

18. Distribution Statement

Motorcycle helmet laws.

Helmet use.

Motorcycle fatalities and injuries.

This report is available from the National Technical Information Service, Springfield, Virginia 22161,

(703) 605-6000, and free of charge from the NHTSA website at www.nhtsa.dot.gov

19. Security Classif.
(of this report) unclassified

20. Security Classif. (of this page)


21. No. of Pages


22. Price


Form DOT F 1700.7 (8-72)          Reproduction of completed page authorized