Study on Section Division of Long-Distance Continuous Tunnel Group

The division of long-distance continuous tunnel groups according to the original standard ignores the visual load of drivers entering and leaving the tunnel many times and the fatigue accumulation of long-time driving, so the long-distance continuous tunnel groups are divided according to the physiological and psychological state of drivers. It provides a theoretical basis for the safety design of tunnel groups. Relying on the tunnel group of Luding to Kangding section of Yakang Expressway, the changes of pupil diameter, heart rate and subjective psychological feelings of drivers are studied and analyzed by combining real vehicle test, indoor test and questionnaire investigation. The results show that: the initial fatigue time of drivers is 15~25 min. The result of the questionnaire survey shows that the drivers feel nervous after passing through 4 tunnels in 15min, and the indoor test results show that the drivers feel uncomfortable after passing through 4 tunnels in 15 min. The tunnel group whose total mileage exceeds the driving distance of 15 min or the total number of tunnels more than 4 within 15min distance is called long-distance continuous tunnel group, and relevant measures should be set up to ensure traffic safety.