Results indicate that in Norway and Sweden, law enforcement efforts have had a substantial control effect on traffic accidents, as evidenced by the negative influence of convictions on accidents. In Norway, license withdrawal had a negative impact on accident rates, and a similar negative impact was associated with jail terms in Sweden. Thus, law enforcement efforts and sanctions do work. Using estimates of the effects of increased law enforcement efforts on lives saved and the value of lives so saved versus costs produces a ratio of marginal benefits to marginal costs of between .183 and .433 for Norway in 1970, suggesting that in terms of social costs, such increased effort is not cost effective. This is not to say that law enforcement efforts should be reduced. Results do, however, suggest that higher fines may be more effective in terms of overall costs. Tables and footnotes.