Fig. 2
Specific environment design in Zhongnanshan Tunnel of G65 Baotou–Maoming Expressway, China. a Connection section of short tunnel; b lighting section inside long tunnel
Fig. 2 | SpringerPlus
Specific environment design in Zhongnanshan Tunnel of G65 Baotou–Maoming Expressway, China. a Connection section of short tunnel; b lighting section inside long tunnel