The heterogeneity of travel mode choice behavior under unplanned metro service disruptions

With the increasing frequency of unplanned service disruptions in metro system, understanding the travel mode choice behavior is essential for the improvement of passenger evacuation strategies and enhancement of metro system security. Individuals' choice behavior may exhibit heterogeneity, particularly when faced with diverse activities and multimodal transport modes. Based on the survey data of Xi'an, China, an error component mixed logit model was developed to explore the decision-making mechanism of mode choices and heterogeneous preferences for multimodal transport modes. The results indicate that activity-dependent attributes significantly influence mode choices. Longer travel distance increases the likelihood of individuals continuing metro travel. Activity urgency level has a significant negative effect on waiting for service resumption, but positively influences the choice of taxis. Furthermore, significant heterogeneity is observed in waiting tolerance and preferences for intermodal transport modes. These findings provide insights for the emergency management of metro system under unplanned service disruptions.