In this driving simulator study the effects of a LDWA-system were investigated under different conditions. These conditions consisted of narrow lanes and a distraction task. Because of possible safety reasons this experiment could not be performed on the road. It was assumed that in these conditions a LDWA system would especially be useful in supporting drivers to keep their lane. A truck driving simulator experiment was performed. In this experiment seventeen professional truck drivers drove for a total of sixteen drives, each under different conditions. These conditions consisted of the combinations of four cross sections, the mode of the LDWA system (on or off) and the presence or absence of a distraction task. The subjects drove on a three lane motorway. The right lane configurations included a lane width of 3.50 m, 3.10 m and 2.90 m, all with an emergency lane, and a lane width of 3.10 m without an emergency lane. Subjects drove on the right lane and were instructed to keep this lane. When the LDWA system was switched on it gave a loud sound (a beep) when the left or right lane marking was being crossed. The distraction task consisted of typing four digits on a numerical keypad. The results showed positive effects of LDWA with respect to driving behaviour on narrow lanes. When the LDWA system was active the duration of lane deviations decreased, subjects swerved less, and the average minimum time-to-line crossing to the right lane marking increased. However, this effect of LDWA depended upon cross-sections. The effect was clearly present on the narrow lanes (< 3.50 m). In general, the distraction task decreased driving performance. The results showed that when subjects had to perform the distraction task driving performance was better with the LDWA system than without the LDWA system. Furthermore, the driving performance was 'better' when subjects drove with the LDWA system and had to perform the distraction task than when subjects drove under normal conditions (no LDWA system, no distraction task). However, the results also indicated that subjects experienced more 'effort' when driving with the LDWA system. The results of the present experiment clearly indicate positive effects for LDWA with respect to lane widths and driver distraction. Narrow lanes (< 3.50 m) benefit most of a LDWA system. The LDWA system reduced the negative effect of effect ofeduced the negative effect of the distraction task on driving performance to a level that the driving performance was 'better' than normal driving (i.e., driving without a system and without a distraction task). However, these benefits come with a price, namely the increased effort when the LDWA system is on. (Author/publisher)
Samenvatting