States that require people over 85 years old to renew their licenses in person recorded a 17% reduced risk of traffic death for these motorists, according to a study in the Journal of the American Medical Association.

David Grabowski, an assistant professor of healthcare policy at the University of Alabama at Birmingham, and his colleagues examined 10 years’ worth of state-by-state data on fatal crashes from the National Highway Traffic Safety Administration and compared the states’ licensing policies. The policies included in-person license renewal, frequency of license renewal, vision tests and road tests.

The researchers found that 45 states required in-person renewal, 40 required vision tests, while only two states required older drivers to take a road test.

Older drivers are responsible for 14% of all traffic fatalities, but that number is expected to nearly double by 2030, according to the study.