Oct 11, 2021 · Jingyuankou tunnel (2272m) in Gutian section of Xiamen Chengdu Expressway in Fujian Province was used as a pilot project to add LED solar road studs. The use of solar road stud not only increases the tunnel identification, but also helps drivers to judge the tunnel width, and also reduces visual and mental fatigue. In view of this pilot application effect, Longyan Expressway plans to add LED solar road studs to other long tunnels along the line.