Panel Paper: Graduated Driver Licensing Laws, Teen Licensure, and Vehicular Fatalities

Thursday, November 8, 2018
Madison B - Mezz Level (Marriott Wardman Park)

*Names in bold indicate Presenter

Gregory Gilpin, Montana State University

Between 1996 and 2015 vehicular fatalities per capita involving 16- and 17-year-old drivers declined by 68.7 percent. During the same period, states enacted graduated driver licensing (GDL) programs that required teens to advance through a series of gates and restrictions to obtain full licensure, reducing driver licensure per capita by 33.3 percent. While the literature has demonstrated that higher-rated GDL programs reduce teen vehicular fatalities, how these reductions occur remains open. In this study, individual GDL provisions are studied to understand the mechanism reducing vehicular fatalities. The evaluation is based on a state-by-year panel and uses difference-in-difference and triple difference specifications to identify causal impacts of GDL provisions on rates of driver licensure, vehicular fatalities, and vehicular fatalities per licensed driver.

The empirical results indicate that only half of the GDL provisions have any impact on vehicular fatalities and licensure. Specifically, a minimum intermediate licensing age of 16.5 or older reduces vehicular fatalities and licensure by 14.0% and 34.9%, by far the largest impact. Nighttime driving restriction reduces licensure by 9.4%, but no effect on fatalities. Teen cellphone/texting bans reduce licensure by 9.4% and fatalities by 6.8%. Mandating supervised driving hours has no effect on licensure, but increases fatalities by 6.9%. All impacts dissipate as teens age and have small, negligible effects beyond age 17. Lastly, GDL provision have small impacts on fatalities per licensed driver for those 16-17, suggesting weak programmatic effect and strong incapacitation effects