Abstract: For the sake of examining the visual characteristics of drivers having different amounts of experience in driving and driving through an extremely long freeway tunnel, real-vehicle tests were conducted, in which 29 drivers' visual feature parameters were recorded real-time by using an eye tracker. Visual feature indexes were obtained, including fixation duration, fixation point location, saccadic duration, saccadic frequency and saccadic amplitude. Variance in eye movement behavior was analyzed by using statistical methods, and influences of driving experience and environment on driving safety were investigated. The results demonstrate that in comparison with driving on a section of an open road, mean fixation duration is longer and range of horizontal fixation point positions is wider in the fairly long tunnel while range of vertical fixation point positions is narrower, saccadic frequency is higher and saccadic amplitude is smaller, and that compared with inexperienced drivers, experienced drivers have shorter fixation duration and wider range of fixation point positions, while their saccadic frequency is lower and saccadic duration is shorter.

Key words: expressway, extra long tunnel, drivers, visual characteristics, eye movement behavior