Safety Evaluation of Tunnel Group on Freeways in Mountainous

Abstract:

In order to improve the safety performance of tunnel group on freeways in mountainous areas, the effects of structure length and geometric alignment of tunnel group on vehicle speed difference and heart rate increment of drivers are quantified through the analyses of changes in vehicle speed at specific sections and psychology and physiology indices for drivers on tunnel group segment. For tunnel group composed of two tunnels, the research results show that the effect of the lengths of previous tunnel and tunnel linkage section on maximum speed difference of small vehicles at tunnel linkage section is relatively obvious, and the effects of length and grade of tunnel linkage section on maximum speed difference of large vehicles at tunnel linkage section is relatively large; heart rate increment of drivers at the exit of the first tunnel is largely affected by the length of previous tunnel and tunnel linkage section, and heart rate increment at the entrance of the second tunnel is largely affected by the length of tunnel linkage section and combined influence of horizontal and vertical alignment of tunnel entrance. On the basis of validation of prediction models with the combination of existing research findings, safety evaluation methods based on speed difference and heart rate increment are provided in the paper.