LAUSR

Abstract Stairs are usually one of the most important evacuation routes in emergencies, such as serious fire accidents or other emergencies. However, experimental data on human movement characteristics on stairs under invisible conditions are limited. A series of pedestrian evacuation experiments were conducted on a staircase to uncover typical behavior characteristics of staircase evacuation for both ascent and descent without visibility. After obtaining the trajectories of pedestrians by video tracking technology, the route-choice behavior, speeds on the stairs and speeds on the landing were analyzed. Firstly, results demonstrate that pedestrians tend to use the enclosure for help when ascending and descending without visibility for safety consideration, and offset angle is correlated with pedestrians’ route-choice behavior. Interestingly, there is no significant difference of speeds on the stairs between ascent and descent, which is different from the finding that descending is faster than ascending under good visibility conditions. Further detailed features including density-speed relations, headway-speed relations and speed-amplitude relations for both upward and downward are discussed. Especially, it is found that the headway-speed relation on the stairs has a correlation with tread depth and arm length due to the constraint of staircase structure as well as the touch behavior. Finally, it is discovered that the mid landing has different effects on speed between ascending and descending. When stepping on the landing, people lengthen stride lengths and increase speeds during ascending, but they shorten strides and decrease speeds during descending. These enrichments are helpful to understand pedestrian evacuation characteristics on stairs without visibility.