The alleged `fleet driver effect' is that drivers of company cars make abnormally high contributions to the numbers of road accidents. This paper presents a Transport Research Laboratory (TRL) study of the evidence for the existence of such an effect, and, if it exists, its likely size, the factors contributing to it, and the measures used to reduce it. The study re-analysed data from the TRL programme of accident liability studies, reviewed the literature on fleet safety with special reference to remedial measures and the evidence for their effectiveness, and did some qualitative research with fleet managers, trainers, drivers, and insurers. Company fleets vary enormously in size and function, and the population of company car drivers is even more diverse. At least seven reasons have been proposed to support the argument that fleet car drivers have higher accident rates than private car drivers. A simplified multivariate model was fitted to the TRL data, and it was found that fleet drivers have up to 50% more accidents than private drivers, even allowing for their greater annual mileage; the reasons for this are not yet clear. There is little evidence that measures currently used to improve fleet safety are actually effective. Fleet safety is most likely to be improved by an integrated set of measures based on a strong company safety culture.
Abstract