According to a new study of crash fatality data from 2000 to 2004 by the National Highway Traffic Safety Administration (NHTSA), states with primary seat belt laws have a 17% lower highway fatality rate than those with secondary seat belt enforcement alone.

NHTSA’s study found that the fatality rate per 100 million vehicle miles traveled (VMT) in states not having primary enforcement laws was 1.21, compared to 1.03 in states with primary enforcement, or 17% higher.

According to Phil Haseltine, executive director of the National Safety Council’s Air Bag & Seat Belt Safety Campaign, this new study by NHTSA complements a large body of research showing that states with the lowest seat belt use generally have weak secondary laws requiring officers to witness another traffic law violation before stopping someone for not buckling up.

To date, 24 states and the District of Columbia have passed primary enforcement laws allowing law enforcement officers to stop and ticket drivers based solely on a seat belt violation. Seat belt use averages 11% higher in states that have primary enforcement laws.

“The evidence is clear that the cost of a weak seat belt law is precious lives lost, and often young lives,” said Haseltine. “It's time for our elected leaders to treat seat belt laws like other traffic laws, enact laws and eliminate crippling secondary enforcement provisions.”