Car Driver Inactivations in Real-World Precrash Phase

This study discusses the potential influence of non-driving tasks on the performance of drivers and on the increased risk of involvement in a traffic accident. It is based upon a review of the literature and results of two research projects carried out in France.

As a complement to experiments on avoidance maneuvers in a simulated accident situation, subjects were asked to rate both their frequencies and subjective risk level for 18 actions involving secondary tasks such as using a phone when driving. Answers given by French subjects are compared to those given by Japanese subjects. It was clear that actions considered as risky are seldom declared and that secondary tasks are often considered as risky whenever they require hand or visual distraction.

The accident sample contains several hundred personal injury car crashes, studied in-depth and on the scene from 1995 to 1999 by a team of accidentologists including a psychologist. All the accidents were investigated using a cognitive and a full cinematic reconstruction of the pre-crash phase. Driver functional failures and error mechanisms, although not directly observable, are inferred from the characteristics of the task and the external appearance of the error. Driver functional failures and error mechanisms (risk taking, unavailability of information, personal errors and under-activation) are analyzed. It appeared that secondary tasks have a low prevalence amongst at- fault drivers but should be considered as contributing to the accident.