Abstract
In countries with a high motorbike utilization rate, road tunnels can feature motorbike lanes, bringing an additional risk to evacuation from tunnels during a fire or emergency. To better understand the walking speed in motorbike lanes to enhance risk assessment in tunnels, in the present study, we conducted evacuation experiments to investigate the influence of motorbike and evacuee density on the walking speed of motorbike users. According to the experimental results, the walking speed was slightly reduced even when the evacuee density was relatively lower (around 0.1 person/m2). To further analyze the influence of motorbikes in the lane, the walking speed decreased significantly with the increase in motorbike density. The decrease in walking speed presented an exponential relationship with evacuee and motorbike density. Considering this exponential relationship, nonlinear regression was applied to estimate the parameters of the walking speed model. The proposed model consisting of the evacuee density, motorbike density, and free walking speed as variables can serve as an approach to describe the walking speed of motorbike lane evacuation in tunnels.