AbstractContextCoverage and enforcement provisions of safety belt use laws vary by state. Most laws cover drivers and passengers age 16 and above. “Primary” enforcement laws allow police to stop and ticket a motorist for a safety belt law violation. With “secondary” enforcement laws, ticketing can only occur in the presence of another traffic infraction. Given the lower rates of restraint use among teen drivers and their passengers, the effect of primary enforcement laws on the restraint use of young teen passengers is of particular interest.ObjectiveTo compare restraint use by 13–15 year olds passengers in motor vehicle crashes in states with primary versus secondary enforcement safety belt laws.MethodsCross-sectional study of 3953 crashes involving 5372 children, representing 54,226 children aged 13–15 years in 41,198 crashes of insured vehicles in 16 states and Washington, DC between December 1, 1998 and December 31, 2004, with data collected via insurance claims records and a telephone survey.ResultsNon-use of restraints by 13–15 year olds was 7.2% (95% CI 4.3–10.1%) greater in secondary enforcement states (10.8%) as compared to states with primary enforcement laws (3.6%). After controlling for driver's age and restraint status and the seating row of the occupant, a 13–15 year olds was over twice as likely to be unrestrained in a secondary enforcement state as compared to a primary enforcement state (adjusted RR=2.2, 95% CI 1.5–3.1).ConclusionsStates considering primary enforcement provisions to their restraint laws should consider the potential benefits these laws may have to all occupants in the vehicle, particularly young adolescents who are nearing driving age.