Analysis on Fixation Distribution Characteristics of Drivers in Long Freeway Tunnels

Abstract

Driver’s fixation Characteristics can express visual information processing course, studying on driver’s eye fixation characteristics during freeway tunnels is necessary to evaluate the safety of tunnel environment. By using IViewX HED Laptop system, driver’s eye fixation characteristics were taken as research objects, 4 typical long tunnels on the same freeway were selected, 32 times valid experiment were carried out for 8 drivers. The distribution characteristics of eye fixation point were obtained, tunnel stage was divided into 7 stages and comparative analysis of eye fixation characteristics was made by 7 different stages. Whether in daytime or at night, the lower limit of the fixation points range is significantly larger than the minimal safe brake time (0.5s), the barycenter of the eye fixation distribution is lower than the eye horizontal line, the areas of plane distribution range at 7 different stages can be sequenced from big to small as: normal stage after the tunnel exit>normal stage before the tunnel entrance>light adaption stage inside the tunnel >middle stage in the tunnel>light adaption stage (50m’s distance before the tunnel exit)>dark adaption stage inside the tunnel >dark adaption stage (50m’s distance after the tunnel entrance). The analysis can lead to the conclusion, the visual load during dark adaption stage inside the tunnel is much heavier than light adaption stage, the visual load at tunnel entrance and tunnel exit is much heavier than on the middle stage of the tunnel, which makes drivers more easily miss road information during the tunnel stage. So it is necessary to set up road signs and markings based on the distribution range of driver’s eye fixation characteristics in freeway tunnels.