Passenger evacuation for ultra-long escalator malfunctions under high passenger flow in multi-level ultra-deep metro interchange hubs

In cities with limited existing space, the construction of new metro stations increasingly focuses on efficient and intensive land use, with station designs trending towards deeper and more complex structures. Station escalators are now designed to span multiple levels and greater heights. High passenger flow in metro transfer hubs increases the risk of crowd congestion and stampede accidents during emergencies, making extra-long escalators a focal point of concern. Using Chengdu's Luomashi Station, a metro hub where four metro lines intersect, as a case study, we propose an integrated modeling method using Revit and MassMotion to account for the extensive underground space, multiple levels, and complex internal structure of ultra-deep transfer hubs. We simulate the impact of long escalator malfunctions on passengers within these hubs. By setting up scenarios of escalator failures and analyzing congestion causes from a micro perspective, we propose evacuation strategies such as directional restrictions and passenger flow guidance to reduce decision-making time, prioritize safe travel for more passengers, and alleviate congestion caused by escalator malfunctions.Quantitative evaluations of exit times and origin destination (OD) social simulation costs reveal that while the walking and waiting costs may increase for passengers in certain directions, overall travel time decreases. This research provides valuable references for metro operators in formulating contingency evacuation plans.