How Long is Really a Road Tunnel? Application of Driving Simulator for the Evaluation of the Effects of Highway Tunnel on Driving Performance

The topic of road tunnel is really a huge question as demonstrated by several fields of research that analyse the tunnel features from different perspectives and with different objectives, from the design to the safety. What is absolutely unique for this road structure in terms of driving exercise is the way drivers behave inside road tunnel as well as approaching it and exiting from it. The study of human factors related to road tunnel is therefore a huge topic of research. The present paper wants to contribute to the knowledge of the tunnel effects on driving performance using the advanced technology of driving simulation in virtual reality. An highway scenario with six twin tube tunnels is reproduced in CRISS driving simulator and the longitudinal speed, acceleration and lateral position of twenty drivers are recorded, post processed and compared with the data of a control scenario, driven by the same sample of drivers, that has the same road geometries and alignment of the tunnel scenario, but without any tunnels. It is found that drivers tend to move away laterally from right tunnel wall when they drive inside the road tunnel and that they slightly slow down. Moreover a preliminary attempt to determine the length of the road segments before and after the tunnel where drivers performance are still influenced by the tunnel is developed and proposed. More specifically in this paper the authors: a) provide the reader with an overview of the application of driving simulation to road tunnel studies all over the world; b) present the main results of a preliminary study, developed with driving simulator, on the dynamic and cinematic effects of road tunnels on driving behaviour; c) discuss the future perspective and opportunities of the study of road tunnels with driving simulator.