Towards an understanding of driver inattention: taxonomy and theory.

There is little agreement in the scientific literature about what the terms "driver distraction" and "driver inattention" mean, and what the relationship is between them. In 2011, Regan, Hallett and Gordon proposed a taxonomy of driver inattention in which driver distraction is conceptualized as just one of several processes that give rise to driver inattention. Since publication of that paper, two other papers have emerged that bear on the taxonomy. In one, the Regan et al taxonomy was used, for the first time, to classify data from an in-depth crash investigation in Australia. In the other, another taxonomy of driver inattention was proposed and described. In this paper we revisit the original taxonomy proposed by Regan et al. in light of these developments, and make recommendations for how the original taxonomy might be improved to make it more useful as a tool for classifying and coding crash and critical incident data. In addition, we attempt to characterize, theoretically, the processes within each category of the original taxonomy that are assumed to give rise to driver inattention. Recommendations are made for several lines of research: to further validate the original taxonomy; to understand the impact of each category of inattention in the taxonomy on driving performance, crash type and crash risk; and to revise and align with the original taxonomy existing crash and incident investigation protocols, so that they provide more comprehensive, reliable and consistent information regarding the contribution of inattention to crashes of all types.