Transfer time optimisation in public transit networks: assessment of alternative models

In transfer-based transit networks, it is critical to synchronise timetables of intersecting routes to reduce passenger transfer times. To this end, this study compares different transfer time optimisation approaches and investigates their solutions comprehensively at the network level as well as for each transfer node individually. Additionally, it assesses the assumption of available bus capacity, which has not received adequate attention in previous studies. Four models are tested through a numerical analysis of a network consisting of three nodes under different headway policies to provide agencies and researchers with critical insights into improving transfer coordination. The results show that the incorporation of demand into the objective function and the inclusion of bus capacity constraints have notable effects on model outcomes. Also, the study highlights important transfer node characteristics which should be considered in the choice of appropriate transfer optimisation models.