Individual route choice behavior in evacuation considering avoidance and phototropism: An experimental study

During an emergency evacuation in a building, participants' evacuation signs obedience behaviors have a significant impact on evacuation efficiency, while participants' possible phototropism and hazard avoidance behaviors occur during evacuation, which will affect evacuation efficiency. To investigate the effects of participants' phototropism and hazard avoidance behaviors on compliance with evacuation signs. One pre-experiment and four groups of evacuation experiments were conducted in the T-junction and Room of the building with a total of 170 participants. A fumes generator and searchlight to simulate light and fumes conditions under fire. Using the statistical analysis to explore the differences in the route choice behavior of evacuees under different conditions. The results show that: (1) In the natural state, participants showed significant phototropism and hazard avoidance. (2) Phototropism and hazard avoidance affect participants' obedience to evacuation signs. (3) In the room scene, participants demonstrated more obvious phototropism and hazard avoidance, even deviating from the evacuation sign's guidelines；(4) Participants showed some decision inertia during two consecutive decisions. Further combined with SHAP interpretable machine learning for analysis, it was found that (1) Scene conditions exist for phototropism and hazard avoidance in evacuees. (2) Fumes prevented participants' obedience to the evacuation sign, whereas light promoted participants' obedience to the sign. This indicates that evacuation signs need to be installed regarding the actual building structure. These findings can be used as theoretical references for building safety design, campus safety, and evacuation simulation tests.