Assessing the efficiency of priorities for traffic law enforcement in Norway

This paper assesses the efficiency of priorities for traffic law enforcement in Norway. Priorities are regarded as efficient if: (1) enforcement ensures a sufficient level of deterrence to keep down the rate of violations; (2) selection of target violations for enforcement is based on the risk attributable to them; and (3) an optimal level of enforcement is selected, i.e. the marginal benefits of enforcement in terms of preventing accidents equal the marginal costs of enforcement. The efficiency of current traffic law enforcement in Norway is assessed in terms of these criteria. It is found that the risk of apprehension varies considerably between different traffic violations. These variations do not reflect the risk attributable to the violations, i.e. it is not the case that the risk of apprehension is higher for violations that make a large contribution to fatalities and injuries than for violations that make a smaller contribution. In principle, shifting priorities so as to increase the risk of apprehension for some violations and reduce it for other violations could make police enforcement slightly more efficient. The main finding, however, is that the current level of enforcement is too low. Cost-benefit analyses show that substantially increasing the amount of police enforcement is cost-effective.