Interacting Drivers at Intersections: What Can Make Them More Safe and More Efficient?.

Technological applications not only affect individual behaviour in traffic, but also influence interaction behaviour. However, not much research has been conducted in this area. This paper attempts to fill the gap by investigating the effects of manipulations of the time and space ("interactionspace") drivers have to safely negotiate an intersection. Interaction space was manipulated by providing drivers at intersections with information about other approaching drivers, and also by varying the expectedness of the approach speed of the other driver. An experiment was conducted using an innovative and promising approach with two linked driving simulators, where participants (N=26) were provided with in-vehicle information (flashing lights in their dashboard and beeps), indicating the direction and speedwith which another driver approached on the intersecting road. Based on the right of way regulation, speed could be either expected or unexpected. The use of linked simulators allowed the participants to interact with a real driver (the experimenter), rather than with pre-programmed drivers andthus provided important information concerning the interaction process. Different behavioural indicators of the safety and efficiency of the interaction process were recorded. Also, concerning the information provided, the level of acceptance and experienced mental effort is reported. The results regarding the behavioural indicators suggest a proactive and reactive stage within an intersection approach, where the latter stage seems more prone to manipulations of interaction space. The acceptance results indicated that the lights were not appreciated whereas the beeps were regarded as quite useful. Mental effort was (subjectively) lower in the condition where extra information was provided. This experiment provides a valuable indication of the effect information would have on driving behaviour, althoughit should be noted that the precise way information was provided here is too simplistic for direct application in real traffic. The full text of this paper may be found at: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv21/09-0240.pdf For the covering abstract see ITRD E145407.