Driver License Renewal Policies and Fatal Crash Involvement Rates of Older Drivers, United States, 1985–2011

In many respects, older drivers are among the nation’s safest road users. They tend not to drink and drive, and they frequently buckle up, avoid distractions, and self-regulate their driving to relatively low-risk times and conditions.

Research has shown that older drivers pose less risk to other motorists and road users than younger drivers do; however, their crash involvement rates increase slightly after about age 75, and due to fragility that comes with age, they are much more likely to be severely injured or killed if they are involved in a crash.

Many states try to keep older drivers and the people with whom they share the road safe through laws and policies related to driver license renewal. To date, however, little is known about the effectiveness of these policies.

Overview

• Objective: Examine the relationships between fatal crash involvement rates of drivers 55 – 64, 65 – 74, 75 – 84, and 85+ in relation to state driver license renewal laws and policies.
• Methods: Data from 46 states from years 1985 – 2011 were examined.
  Population-averaged negative binomial regression was used to estimate the impact of policies on fatal crash involvement rates while adjusting for the effects of other factors.*

Key Findings

• Requiring license renewal to be conducted in person was associated with a 9% reduction in fatal crash involvement rates for drivers 55+ and a 25% reduction for drivers ages 85+.
• Enacting or repealing a requirement for mandatory vision testing at license renewal was not associated with any significant change in fatal crash involvement rates for older drivers.
• Drivers ages 85+ had lower fatal crash involvement rates in states that required vision testing than in states that did not; however, given the lack of evidence of changes in safety following changes in vision testing requirements, these differences may be due to other factors besides the vision testing requirements.
• Increasing the frequency of license renewals, requiring drivers to pass a knowledge or on-road test, and mandating physician reporting of drivers were not associated with statistically significant reductions in fatal crash involvement rates.

Discussion & Additional Information

• This study presents strong evidence that requiring drivers to renew their licenses in person is associated with significant reductions in population-based fatal crash involvement rates.
  • This is consistent with a 2004 study of 11 years of data from all U.S. states that found mandatory in-person renewal was associated with a 17% reduction in daytime fatalities of drivers ages 85+.**
  • Study could not identify specific ways that mandatory in-person renewal reduces crash rates. Possibilities include:
    • Self-imposed driving cessation among drivers who are afraid or unable to go to the DMV to renew their license in-person;
    • DMV office staff identify drivers with problems that may impact their driving and refer those drivers for additional evaluation, as was observed in a previous AAA Foundation study in the state of Missouri; or,
    • Likely, some combination of both.
• More research is also needed to better understand the effects of mandatory vision testing.
• Despite having 27 years of data from each of 46 states, there was not enough data to draw confident conclusions about some driver licensing policies:
  • Only three states required all drivers over a specified age to take an on-road driving test at routine in-person license renewal, and of those, two were in effect for essentially the entire study period; thus, there was very little data with which to investigate the effect of implementing or repealing such a requirement.
  • No differences in crash rates of older drivers were observed in states with vs. without laws mandating that physicians report drivers about whom they are concerned. Directly assessing the effects of changes in laws might have provided insight, but that was not possible since no state implemented or repealed such a law during the study period.