Primary seat belt enforcement laws

Evidence Rating  
Evidence rating: Scientifically Supported

Strategies with this rating are most likely to make a difference. These strategies have been tested in many robust studies with consistently positive results.

Health Factors  
Decision Makers
Retired Strategy

Retired strategies are no longer updated.

Date last updated

Primary seat belt enforcement laws allow law enforcement officials to stop drivers solely for failing to use a seat belt1. Primary seat belt laws differ from secondary seat belt laws, which allow police officers to issue a seat belt citation only after stopping the driver for another reason2.

What could this strategy improve?

Expected Benefits

Our evidence rating is based on the likelihood of achieving these outcomes:

  • Increased seat belt use

  • Reduced fatal and non-fatal injuries

What does the research say about effectiveness?

There is strong evidence that primary seat belt enforcement laws increase the use of seat belts1. Primary enforcement laws increase seat belt use and reduce fatal and non-fatal injuries more effectively than secondary enforcement laws1.

States that change from secondary to primary seat belt enforcement laws have increased rates of seat belt use after primary enforcement laws go into effect3. Changing from secondary to primary enforcement has been shown to increase seat belt use during the day and night4. Primary enforcement laws appear to have the largest effects among high-risk drivers, such as alcohol-impaired drivers, and among populations with lower rates of seat belt use, such as blacks and Hispanics3.

Despite concern, there is no evidence that minorities are stopped at higher rates than whites for seat belt violations in states with primary enforcement laws. Several states have added anti-harassment language to their primary seat belt laws to reduce the risk of such differential enforcement3.

Primary law enforcement can include paid media efforts5, 6. Primary seat belt laws that are enforced with well-publicized seat belt use checkpoints appear to yield more benefits through quality adjusted life years (QALYs) saved and injuries prevented than they cost to implement7.

How could this strategy impact health disparities? This strategy is rated likely to decrease disparities.
Implementation Examples

As of May 2015, 34 states and Washington, D.C. have primary seat belt laws for front seat occupants; in 17 of these states and Washington, D.C., primary enforcement laws also cover rear seats8.

Footnotes

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1 CG-Motor vehicle injury - The Guide to Community Preventive Services (The Community Guide). Motor vehicle injury prevention.

2 NHTSA-Goodwin 2013 - Goodwin A, Sandt B, Hall W, Thomas L, O’Brien N, Summerlin D. Countermeasures that work: A highway safety countermeasure guide for state highway safety offices, 7th edition. Washington, D.C.: National Highway Traffic Safety Administration (NHTSA), U.S. Department of Transportation (U.S. DOT); 2013.

3 Dihn-Zarr 2001 - Dihn-Zarr TB, Sleet DA, Shults RA, et al. Reviews of evidence regarding interventions to increase the use of safety belts. American Journal of Preventive Medicine. 2001; 21(4S):48-65.

4 NHTSA-Chaudhary 2010 - Chaudhary NK, Tison J, Casanova T. Evaluation of Maine's seat belt law change from secondary to primary enforcement (Report No. DOT HS 811 259). Washington, D.C.: National Highway Traffic Safety Administration (NHTSA), U.S. Department of Transportation (U.S. DOT); 2010.

5 NHTSA-Nichols 2010 - Nichols J, Tippetts AS, Fell J, et al. Strategies to increase seat belt use: An analysis of levels of fines and the types of law. Washington, D.C.: National Highway Traffic Safety Administration (NHTSA), U.S. Department of Transportation (U.S. DOT); 2010.

6 NHTSA-Hedlund 2008 - Hedlund J, Gilbert SH, Ledingham K, Preusser D. How states achieve high seat belt use rates. Washington, D.C.: National Highway Traffic Safety Administration (NHTSA), U.S. Department of Transportation (U.S. DOT); 2008.

7 Miller 2000 - Miller TR, Levy DT. Cost-outcome analysis in injury prevention and control: Eighty-four recent estimates for the United States. Medical Care. 2000;38(6):562-82.

8 GHSA-Seat belt laws - Governors Highway Safety Association (GHSA). Seat belt laws.