Abstract
In case of massive fire incidents in tunnels, ceiling lights are covered by dense smoke, and pedestrians must evacuate in the dark tunnel with almost zero visibility. Nonetheless, the walking behavior in a completely darkened tunnel has not been clarified. In this study, we experimentally attempted to investigate the evacuation loci and assess the stress of evacuees by measuring oxytocin and cortisol concentrations in saliva, heart rates, blood pressures, and responses in a survey questionnaire for a full-scale tunnel. Results indicated few differences in both one- and two-dimensional walking speed. In terms of stress, the group of subjects who felt stress demonstrated a walking speed that is 0.17 m/s slower than the group that did not feel it. In the questionnaire survey, most of the subjects answered that the wall was the most helpful item, followed by the unevenness (bumps) on the white lines on the road. One of the subjects became lost, stating that she could not find the unevenness (bumps) on the white lines. These two factors can be rational guides in a dense smoke environment or a completely dark tunnel scenario.
Highlights
The typically long and enclosed geometry of tunnel spaces contributes to difficulties in the evacuation, rescue, and firefighting operations in tunnels, given that even the slightest of incidents produce possible significant losses, e.g., human casualties or economic slowdowns, as demonstrated by tunnel fire incidents in the past
In case of a massive fire, the ceiling lights are covered by dense smoke, thereby reducing the effective visibility for an evacuation
Without regarding the influence of dense smoke and toxic gas on the human body, the walking speed in a dark tunnel may be considered as the slowest evacuation speed
Summary
The typically long and enclosed geometry of tunnel spaces contributes to difficulties in the evacuation, rescue, and firefighting operations in tunnels, given that even the slightest of incidents produce possible significant losses, e.g., human casualties or economic slowdowns, as demonstrated by tunnel fire incidents in the past. An evacuee’s mobility or walking speed in a less visible environment is influenced by insufficient lighting and by stratified dense smoke covering the lighting that may induce forced evacuation in the dark. Togawa [1] approximated that the walking speed in a dark architecture was 0.3 m/s, which was within the walking speed of 0.24–0.88 (average 0.49) m/s that Seike et al [2] have reported, whereas walking behavior in a dark tunnel has not been clarified. Evacuees during the Sekisho tunnel fire accident in Japan [3] were reported to have used their mobile phones’ light, but the mobile light function effect was little due to the dense smoke. Without regarding the influence of dense smoke and toxic gas on the human body, the walking speed in a dark tunnel may be considered as the slowest evacuation speed. If the evacuees’ behavior and the reason for such a tendency
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
