Major Department



College of Liberal Arts & Sciences


BS (Bachelor of Science)

Session and Year of Graduation

Spring 2021

Honors Major Advisor

Steven Stong

Thesis Mentor

Jeffrey DeSimone


We study the impact of Ignition Interlock Laws (IILs), an increasingly popular public policy aimed at reducing drunk driving, on driving under the influence (DUI) arrests. While past studies have found that IILs reduce alcohol-impaired motor vehicle fatalities and short-term recidivism rates, little evidence exists on how IILs impact DUI arrests as a more direct indicator of DUI prevalence. Using state-level monthly panel data from the Uniform Crime Reporting Program, we find that DUI arrests decrease in response to IIL adoption, though more substantively and significantly when all DUI offenders are required to use them for a period after their conviction. The results suggest deterrence may be at least partially responsible for this effect, contrary to what a previous analysis of motor vehicle fatalities concluded. Our results add to the understanding of how IILs work, as policy makers continue to address the over 100 million episodes of driving while potentially under the influence of alcohol that are reported annually.


Ignition Interlock Laws, Driving Under the Influence, Arrests, Public Policy, Drunk Driving

Total Pages

13 pages


Brant Walker acknowledges funding from the Public Policy Center at the University of Iowa and the Iowa Center for Research by Undergraduates.


Copyright © 2021 Brant Walker