Depowering Risk: Vehicle Power Restrictions and Teens’ Driving Accidents in Italy

This paper investigates the road safety impact of a restriction in engine power on novice drivers. The restriction, introduced in Italy in 2011, prevents drivers from using high-performance vehicles during the first year they have their license. To estimate the effect on teens’ traffic accidents, we leverage the between-cohorts difference in exposure to the reform. When prevented from using high-powered cars, teens are 13 percent less likely to cause an accident and 28 percent less likely to cause a fatal accident, mainly because of fewer speeding violations. This effect persists even after the 1-year restriction ends. These findings highlight the importance of targeted policies—directed at those generating the greatest harm—that limit exposure to specific high-risk settings. These policies stand out as an effective yet feasible alternative to deterrence-based strategies and screening mechanisms, which are often difficult to enforce and sustain.