Impact of driver licensing renewal policies on older driver crash involvement and injury rates in 13 states, 2000-2019.

Background: Motor vehicle crashes are the second leading cause of injury death among adults aged 65 and older in the U.S., second only to falls. A common state-level approach to mitigating older adult crash risk is the implementation of driver license renewal policies which vary largely between states and data on their effectiveness in preventing crashes and injuries are limited. To fill this gap, the aim of this study is to examine the association between state driver license renewal policies and older driver crash and injury rates.

Methods: Historical crash data, license renewal policy data, and other relevant policy and demographic data were gathered from 13 U.S. states (CO, IL, IA, KS, MN, MO, NE, ND, OH, SD, UT, WI, WY) for years 2000 through 2019, inclusive. Main exposures included six license renewal policies: renewal period, in-person renewal frequency, vision testing, knowledge testing, on-road drive testing, and mandatory physician reporting. The primary outcomes were crash and injury rates per 100,000 population.

Results: The study population included 19,010,179 crash-involved drivers aged 40 and older. State policies became less restrictive in many states over the study period, even for drivers aged 75 and older, resulting in longer times between renewals and fewer in-person renewal requirements. Loosening of in-person renewal from every time to less than every time was associated with increased crash rates, among drivers aged 65 to 74 (RR_crash = 1.08, 95% CI: 1.01-1.16). A longer duration between in-person renewals was associated with increased injury rates among drivers 75 and older (RR_injury = 1.18, 95% CI: 1.00-1.39).

Conclusions: Generally, state policies became less restrictive and resulted in longer required intervals between license renewal. Loosening of driver license renewal policies was associated with increased crash and injury rates. However, safety benefits of restrictive older driver licensing policies should be carefully weighed against costs to older adult well-being and quality of life following licensure loss. Additional methods to assess fitness to drive are necessary to identify the mechanisms behind the increased rates.