Optimizing Geometry and Frequency of Transit Networks in Heterogeneous Territories

Abstract

Traditional transit network design forces a choice between the structural rigidity of discrete graphs and the oversimplified approach of density-based continuous models. This paper bridges that divide by introducing a novel, corridor-based continuum framework that endogenously optimizes spatial coordinates and line-specific headways of transit networks. Driven by a stochastic routing model and a three-stage hybrid optimization strategy, the framework navigates a highly nonconvex design space while enforcing vehicle capacity at critical transfer nodes.

Our findings highlight a consistent design pattern: while homogeneous layouts provide good strategic guidance, introducing geometric and frequency heterogeneity balances trade-offs between capacity utilization and accessibility across the network under spatially heterogeneous demand. This fine-tuning improves the efficiency of service allocation, enabling operators to reduce costs by over 13% under centralized heterogeneous demand scenarios, resulting in substantial operational efficiency without degrading the passenger experience.