The Dutch Ministry of Transport, Public Works and Water Management is currently preparing plans for building a one-lane tunnel near Nijverdal. Before the final design can be made, some questions still have to be answered. These questions included: Does the road have to be 5.40m, 6.00m or 6.50m wide? Is a maximum speed of 80 or 100 km/h more appropriate? Is the driving behaviour different in case of an open construction of 600m in front of the tunnel or with an entrance of 100m? Is driving behaviour or subjective experience different in case of other traffic on the road? Do the tunnel walls have to be made of a dark or a light colour? What is the expected traffic capacity of the tunnel? To answer these questions, the ministry had TNO Human Factors conduct a driving simulator study. TNO Inro performed capacity estimates of the tunnel. 48 subjects drove various tunnels in the TNO driving simulator, and driving behaviour, workload and subjective experience were measured. At the end of all rides, subjects filled out a questionnaire as well. All roads were divided into 5 road sections. For each road section, we analysed speed, standard deviation of speed, lateral position, standard deviation of lateral position (as a measure for swerving in a lane), how strenuous the steering was, and workload (by means of the Peripheral Detection Task). The differences in road width primarily had an effect on the lateral position. With a wider road, one dares to drive more to the left side of the lane since there is more space available to the wall. With a wider road, people were swerving a little more in their lane, but the differences were fairly small. Furthermore, few other effects were found on driving behaviour. There are a lot of advantages to the 80 km/h road. The effects of a dark or a light wall did not really result in any clear behavioural effects, but subjects stated in the questionnaires that a light tunnel was preferred, although care has to be taken that the yellow light is not too bright. Subjects are not very positive about the open construction of 600m, and some aspects of driving behaviour are also less positive. Driving behaviour with other traffic is very similar to that without any lead vehicle. The capacity estimates of the tunnel indicate that the capacity of the tunnel will still be sufficient in 2020, irrespective of the specific design elements. (Author/publisher)
Samenvatting