Influence of different visual guiding facilities in urban road tunnel on driver's spatial right-of-way perception

Urban road tunnel construction is becoming ever more prevalent, and traffic safety in tunnel operation is even more important. This study evaluates the influence of different visual guiding facilities on drivers' spatial right-of-way perception by combining quantitative and qualitative methods in order to provide a basis for traffic safety optimization in the tunnel. Simulation scenes were designed for six common types of visual guiding facilities as comprising no facility (baseline), horizontal strips, edge markers, LED arch, vertical stripes, and combination (multiple) facilities. An eye tracker was used to obtain eye movement data of subject drivers exposed to various scenes. After each driving test, psychological feeling of the subjects in tunnel driving, and their ratings of alignment and contour guidance of various facilities were obtained by questionnaires. The research results showed that setting locations and facility types have a great impact on drivers' glance location and glance duration. When horizontal stripes, edge markers, LED arch and vertical stripes were set separately, alignment guidance and contour guidance performance were found to vary in inverse proportion. Horizontal stripes and edge markers are the preferred and necessary facilities, which are conducive to ensuring longitudinal and horizontal rights-of-way. LED arch and vertical stripes are also good supplements to spatial right-of-way. The combination of these 4 types of facilities can provide multi-level alignment guidance and contour guidance functions, which is beneficial to traffic safety in the tunnel.