This paper presents the results of some empirical studies of risk compensation processes in relation to anti-lock braking systems (ABS). The following specific hypothesis, resulting from the risk homeostasis theory (RHT), was tested: ABS are not effective in reducing traffic accidents, because they do not belong to the class of safety measures that influence risk acceptance. Thus ABS measures will remain ineffective in the long run, because their potentially positive effects are negated by the more uncautious behaviour of drivers. ABS were chosen because, at the start of the project, they were not yet widespread, but had shown significant safety advantages in tests. The study examined the effects of ABS in actual traffic situations in Germany, and created sufficiently controlled conditions relating to drivers' performance and risks due to external conditions. A sample of Munich taxi drivers were randomly assigned to taxis with and without ABS. Data on accidents were collected during 1981-83 and on acceleration, behaviour and attitudes from 1985-86. The study identified six compensation mechanisms, including: (1) inattentive driving resulting from feeling safer; and (2) overestimation of safety under certain conditions. For the covering abstract see IRRD 870346.
Abstract