["Journal of Policy Analysis and Management, Volume 45, Issue 3, Summer 2026. ", "\nAbstract\nThis paper examines the effect of granting undocumented immigrants driver's licenses on fatal crashes. Using county‐level crash data from the Fatality and Injury Reporting System Tool, I leverage the quasi‐randomness of the timing of the driver's license reforms adoption across states to identify the causal effect of driver's license reforms. My findings show that granting undocumented immigrants driver's licenses increases overall fatal crashes by nearly 5%, equivalent to 0.46 more fatal crashes in a county per year. The effect is stronger in states with a higher population of undocumented immigrants. By investigating the mechanism through which the policy impact is likely to occur, I show that undocumented immigrants may be more likely to engage in risky driving behavior once they obtain driver's licenses. Several robustness checks and placebo tests support my main findings.\n"]