Safety improvement effect of guiding visual reference system in long urban tunnels

In order to ensure traffic safety in long urban tunnels and to improve traffic efficiencyꎬ visual environment characteristics of these tunnels with multiple off ̄ramps were analyzedꎬ and a stereoscopic guiding visual reference system was constructed based on visual illusion mechanism and color psychology principles. Thenꎬ an experiment of drivers ' psychophysics perception was carried out by using E ̄prime software to study the system's effect on improving traffic safety in long urban tunnels and its optimized design. The results show that drivers are most comfortable with blue and green information while yellow has a strong warning effect but causes no sharp stimulusꎬ which enhances driving attention. The reference system effectively shortens drivers' visual recognition time of guiding information and increases recognition distance. In additionꎬ rhythm designs are moderately inclined to the entrance and the exit in order to induce drivers to have reasonable slope illusion. When it is 75° inclinedꎬ drivers can achieve best speed 第 4 期 罗浩顺等: 城市长隧道导向视觉参照系安全改善效果研究 control on tunnel slopes.