Under contract with the Transport Research Centre of the Dutch Ministry of Transport, Public Works and Water Management, TNO Human Factors assessed the comprehensibility of peak-lanes in a mini-simulator. With peak-lanes, the emergency lane is used as a traffic lane in peak hours. Currently, peak-lanes are only used between entries and exits (start at an entry and end in an exit). In this study, we focused on the comprehensibility peak-lanes that are situated alongside entries and exits, meaning they start before the entry and continue after the exit. The Transport Research Centre provided six designs for such peak-lanes, and we evaluated the comprehensibility of every design separately. The idea was not to choose the best design, but to compare every single design with a reference design (peak-lane in between an entry and an exit) and to come up with possible recommendations to improve the designs. Subjects were seated in a mini-simulator, driving on a motorway with a (open or closed) peak-lane. Based on the route signs and green arrows and red crosses above the lanes, subjects had to decide whether the peak-lane was open or not. Altogether, subjects drove all seven designs (reference and six designs), with an open and a closed peak-lane. Sometimes they had to follow the road, sometimes they had to enter the motorway and sometimes they had to take the exit. After each ride, we asked subjects to indicate how well they could understand the situation. No feedback was provided about their behaviour. Other traffic was simulated on the road, and closed lanes were not used by this simulated traffic. We found that quite some mistakes were made. Sometimes these were minor mistakes, for example when subjects did not always use the peak-lane or all available lanes when they were available. Therefore our recommendation is not to separate the two directions too soon. Sometimes however, mistakes were made by driving on a closed peak-lane. Mistakes were primarily made if no signalling was shown during a considerable amount of time/distance. Moreover, on the basis of road markings, people changed their behaviour even though this was not intended with the design. In order to prevent this we therefore advise not to use too many different types of road markings on one stretch of road. It is in this light recommendable to limit the road markings to a block marking, k marking, marking (common when using peak-lanes) and a standard 3-9 marking. We also recommend to use signalling directly after an entry, to avoid that people enter the main road, despite of the fact that the peak-lane is open and to avoid the use of lane while it is actually closed. Furthermore, we advise to always accompany a transition from one type of road marking to another by signalling (arrows and/or crosses) in order to avoid confusion about lane choice. The traffic, present in the lane that later becomes a closed peak-lane (after the exit) should gradually be redirected to the right. Immediately after the exit, a red cross should be positioned above the then closed peak-lane. These measures are meant to avoid confusion about the availability of the exit. (Author/publisher)
Samenvatting