New Requirements for Tunnel Lighting Environment: A Review on Energy Saving and Visual Comfort

Tunnel lighting is important for driving safety in tunnels. Currently, the emphasis on the study of tunnel lighting has expanded from safety to energy saving and visual comfort. This paper makes a bibliometric analysis of relevant literature using CiteSpace, and summarizes the current research trends and future development directions. Firstly, a keyword timeline graph was drawn by CiteSpace to provide a visual representation of the literature in the field of tunnel lighting. Then the literature is reviewed in terms of two aspects: energy saving and visual comfort. Current research mainly focuses on lamps, auxiliary lighting and lighting systems to save energy. With the development of technology, intelligent tunnel lighting control systems can incorporate more control factors and target parameters to further meet the requirement of saving energy. It focuses on the effect of physical quantities (luminance, color temperature, color rendering, etc.) on drivers’ visual comfort. However, there is still room for tunnel lighting to develop in achieving the unity of energy saving and visual comfort.