Shaping the Habits of Young Drivers

Young, inexperienced drivers have the highest risk of traffic accidents. In this paper, we examine a targeted intervention in Australia that banned first-year drivers from carrying multiple passengers between 11pm and 5am. Using daytime outcomes as controls, we find that the reform reduced late-night accidents with multiple passengers by 54% and deaths by 75%, with passengers and other drivers accounting for most of the lives saved. We do not find offsetting effects for other types of accidents. The effects persist beyond the first year, suggesting that the intervention changed the habits of young drivers throughout their highest-risk years.