How to resolve the contradiction between driving safety and lighting energy conservation in a highway tunnel? − An experiment on linear guiding system

High rates of traffic accidents and lighting energy consumption are significant problems in highway tunnels. To address these problems, this study proposes a linear guiding system that uses line-shaped visual guiding facilities to improve the local luminance and contrast, and outlines the tunnel contour and road alignment. In addition, the principle, function, setting method, and composition of the linear guiding system are discussed. Using the existing highway tunnels as prototypes, we built simulation scenarios with different luminance and conducted driving simulation experiments and questionnaire surveys. We analysed the human factor demands of tunnel driving, studied the change rule of various human factor indicators under different luminance levels, and comprehensively evaluated the impact of linear guiding system on driving safety from multiple perspectives of the driver’s vision, psychology, and behaviour. We introduce the concept of equivalent luminance, quantify the impact of linear guiding system on the driver, and explore the role of linear guiding system in energy conservation. The results showed that the linear guiding system has a positive effect on driver vision, psychology, and behaviour, particularly in low-luminance environments. A linear guiding system can optimise a driver’s visual reference frame, enhance driver visual perception in a tunnel environment, and alleviate driver tension. It helps drivers to accurately perceive their own spatial position and speed, providing a good sense of position, speed, and comfort. A 2.3 cd/m2 luminance highway tunnel with a linear guiding system is equivalent to a 4 cd/m2 luminance traditional tunnel. For highway tunnels with luminance values of 4, 5, 6, and 7 cd/m2, the equivalent luminance values of the linear guiding system are 1.7, 1.8, 1.8, and 2.1 cd/m2 respectively, which can reduce the energy consumption by 30–42 %.