The field of view of lorry drivers is limited in more than one direction. Especially the blind spot on the right side of the vehicle has an important link with traffic safety in case of accidents involving vulnerable road users and lorries that make a right turn. Some solutions to this field of view problem are already available. In assignment of the Transport Research Centre of the Ministry of Transport, Public Works and Water Management, TNO evaluated the efficacy of some of these systems. Part I of the project consisted of a study concerning the required field of view and the available field of view. The current report presents the results of part 2, a driver behaviour study. Three systems were examined in a field experiment: an additional mirror, a camera system and rotating main mirror. Lorry drivers drove with an instrumented lorry and their task was to turn right at several intersections and roundabouts. At unpredictable moments in time, a moped drove next to the vehicle. Every lorry driver drove half of the experiment with the standard mirror configuration and half with an additional system. Ten lorry drivers participated per system. In case of the additional mirror and the camera system, a clear improvement was found for detection of the moped compared to the standard mirror configuration. The rotating main mirror only showed an improved detection when the moped was at a somewhat larger distance from the mirror. The area close to the mirrors may be better covered if the vertical field of view of the main mirror would be increased. None of the systems showed an improvement when the moped appeared from the blind spot behind the vehicle. In case drivers could only use the standard rearview mirrors, the percentage of detection errors at r6undabouts was three times as high as the percentage at intersections. The percentage of time that subjects looked to the right side (through the window, in the mirrors or to the systems) did not substantially increase for any of the systems with respect to the standard mirror configuration. For the additional mirror and the camera system the number of glances increased and the dwell times decreased. Overall, subjects looked towards the right side for 40% of the time per manoeuvre for all conditions. On average, the additional mirror was sampled 3.1 times per manoeuvre, the camera system was sampled 2.7 times and the rotating main mirror was used 1.7 times. The average dwell time for the additional mirror was 0.57 s and for the camera monitor 0.56 s. Effects on the spare workload capacity could not be reliably assessed. Questionnaire results showed that subjects rated the three systems rather positively. (A)
Abstract