Rewarding Safe and Environmentally Sustainable Driving

The paper reviews trials designed to reward safe and environmentally sustainable driving. The most common type of trial offered monetary rewards to drivers for not speeding or for reducing mileage. Seven trials were identified. The most successful incentive schemes for reducing speeding were associated with a 60% to 80% reduction of speeding. Trials designed to reduce mileage were not as successful and resulted in mileage reductions of 0% to 10%. Small samples and high attrition rates (i.e., participants dropping out of the study before it was completed) characterized most trials. There is also likely to be self-selection bias, but the size of this bias is difficult to determine. Data for Sweden and Denmark suggest that bias could be substantial. Therefore, the effects found in the trials reported so far reflect what can be accomplished in groups of highly motivated drivers.