关键词: 城市交通, 拥堵成因识别, 状态递推, 出租车接驳, 供需失衡, 乘客弃乘行为

Abstract: To address the difficulty in identifying the causes of taxi transfer congestion at transportation hubs during holidays, this study develops a state-recursion model of queue dynamics based on the principle of flow conservation. A dual-gap congestion diagnosis method is further proposed through consisting of the potential capacity gap and the effective matching gap. The dual-gap indicators enable a stratified identification of the types of supply-demand imbalance. Together with the vehicle utilization rate, empty-departure rate, passenger abandonment rate, and supply-demand response lag, they form a multi-dimensional cause identification framework. This framework systematically characterizes the dynamic evolution of queue accumulation and the temporal mismatch between supply and demand. A case study is conducted by using 5 min observational data from three typical peak days during the National Day holiday in 2024 at Lanzhouxi Railway Station. The results reveal three distinct queue evolution patterns: evening-concentrated imbalance, continuous accumulation, and fluctuating release. These patterns demonstrate pronounced time-of-day dependency and pattern heterogeneity. The overall capacity of vehicles at the hub is sufficient to cover the passenger demand during holidays. Therefore, the primary cause of congestion is not a vehicle shortage but the combined effect of inadequate service conversion and temporal supply-demand imbalance. Passenger abandonment reduces the observed queue length and average waiting time and weakens their ability to reflect the true extent of the imbalance. The proposed method can serve as a reference for congestion cause identification and operational diagnosis at comparable transportation hubs.

Key words: urban transportation, congestion cause identification, state recursion, taxi feeder service, supply-demand imbalance; passenger abandonment behavior