Visual Characteristics of Drivers at Different Sections of an Urban Underpass Tunnel Entrance: An Experimental Study

Abstract

The increase in the number of traffic accidents due to the increasing number of urban underpass tunnels necessitate a better investigation of drivers’ visual characteristics when entering the tunnels. A total of 20 drivers were gathered to perform a real vehicle experiment in an urban underpass tunnel. The saccade angle, saccade frequency, and fixation time were selected as the research indexes. The urban underpass tunnel entrance was divided into five sections, namely the external straight line section, the upper half of the ramp, the lower half of the ramp, the shading shed section, and the entrance inner section. The results showed that the saccade angle and frequency of the ramp were significantly smaller than that of the external straight line and the tunnel interior, and the saccade range in front of the entrance was more concentrated. The changes in fixation time and the difference range of 15th-85th fixation time threshold in each section were analyzed. The fixation time of all sections was distributed within the range of 149.476 to 475.414 ms. The driver’s fixation was more and more concentrated when the sidewalls were higher and closer to the portal.