Study on Luminance in the Threshold Zone of Highway Tunnel

Currently, highway tunnel development is on the upswing. As an important guarantee for traffic safety in highway tunnel, tunnel lighting has a short history of research. Since the 1960s when tunnel lighting began to become a subject of research, it was gradually and profoundly realized that lighting at the tunnel threshold zone was the focus of the entire tunnel lighting. This paper provides a review on past research into tunnel lighting and findings, and then introduces the latest theory and calculation methods regarding the luminance in the threshold zone of highway tunnel with a view to giving some valuable reference for engineering practice.