Risk compensation and the effectiveness of safety belt use laws: a case study of New Jersey

This paper investigates the effectiveness of New Jersey's mandatory belt use law (MUL) by testing specifically for: (1) a safety effect, and (2) a risk-compensation effect that could offset (in part) any safety impact. The main findings are that injury severity declined significantly in the 22 months following implementation of the MUL; but that accident frequency increased significantly. The increase in accidents may be explained only partially by increased driving mileage. These findings suggest that the real safety effect of the law may have been diluted by risk-compensating behavior.This paper is based on a study conducted for the New Jersey Office of Highway Traffic Safety by the Rutgers University Bureau of Economic Research. We are grateful to William Ascher and two referees for useful comments.