Enhancing Equity in Multimodal Public Transport: Optimising Electric-Bus Transfer Stations

As electric buses become increasingly integrated into urban public transport systems, research on their role in transfer networks remains limited. Passengers often encounter extended waiting times during transfers, raising equity concerns. This study formulates a multi-objective mixed-integer quadratic programming (MIQP) model to optimise electric-bus transfer-station planning, considering station-level transfer equity, the surrounding built environment, multimodal transfers involving metro services and taxis, and the operational characteristics of electric buses. The model aims to (1) minimise passenger transfer-time burden, (2) reduce system operating costs, and (3) improve station-level horizontal transfer equity. Sensitivity analyses are conducted for time cost and preference parameters. The Harbin case study shows that, compared with the original scheme, the optimised scheme reduces total transfer time by 11.25%, decreases the variance-based equity indicator by 25.52%, reduces the maximum transfer utility by 14.99%, and lowers annual operating costs by 206,700 CNY. This study provides crucial insights for optimising electric-bus deployment in the broader context of public transport electrification.