The objective was to gain insight in how the number of cyclists, the cyclist's approach direction and the cyclist's action affect speed and mental workload of drivers approaching rural intersections. Also, the effects of a speed-reducing measure on the interaction between cyclists and motorised traffic was examined. An experiment was conducted in a moving-base driving simulator. Thirty participants completed three runs each in three conditions: a baseline, a plateau and a chicane condition. Participants drove an 80 km/h rural distributor road with eight intersections. Eight cyclist scenarios were developed varying in the number of cyclists and the direction from which they approached the participants’ lane. The Peripheral Detection Task was used to measure workload objectively and continuously. A plateau ahead of the intersection resulted in drivers entering the bicycle crossing with lower driving speeds but did not result in less serious potential conflicts compared to intersections without speed-reducing measure. With respect to the presence of cyclists, drivers approaching the intersection without cyclists reached a minimum speed at a larger distance to the bicycle crossing compared to approaching the intersection with multiple cyclists in the baseline condition. At intersections with plateaus, drivers drove slower when encountering multiple cyclists compared to no cyclists. At intersections without speed-reducing measure, drivers drove slower, decelerated stronger and decelerated at a shorter distance to the bicycle crossing when encountering the suddenly crossing cyclist compared to the yielding cyclist. Although having right of way at rural intersections, drivers’ speed behaviour was affected by the number and action of cyclists. From a road safety point of view, driving speeds at rural intersections need to be further reduced to limit the seriousness of potential conflicts between cyclists and motorised traffic. (Author/publisher)
Samenvatting