Exploring Behavioral Responses of Motorists to Risk-Based Charging Mechanisms

This paper reports the behavioral response of motorists in Australia to a variable-rate charging scheme designed to encourage safer driving practices and reduce exposure to crash risk, specifically kilometers driven, nighttime driving, and speeding. The study involved a 5-week before period of Global Positioning System monitoring to establish how motorists drove normally, followed by a 5-week after period of Global Positioning System monitoring in which charges were levied and changes assessed. Incentives were paid to motorists for the difference in the charges between the two 5-week periods. Vehicle kilometers traveled (VKT) was reduced by 10%, although the sample was evenly split into motorists with increasing VKT and those with decreasing VKT. The proportion of distance speeding fell by 4.7%; this finding, when coupled with decreases in VKT, implied a net reduction of more than 40% in kilometers spent speeding. Three-fourths of the participants reduced their speeding. Exit interviews with a cross section of participants highlighted the practical difficulties of reducing kilometers but (more encouragingly) reinforced the potential to reduce speeding.