Operational design for modular electrified transit in corridor areas

In urban corridor areas, profound congestion creates a pressing need for public transit to deliver efficient, flexible, and sustainable "door-to-door" services. This paper introduces a modular electrified transit system tailored for urban corridor areas (MET-CA), with a primary focus on enhancing transportation efficiency and reducing electrical energy consumption. The MET-CA system comprises two core components: mainline transit, dedicated to providing rapid services along the corridor, and feeder transit, catering to individual service zones. Seamless en-route transfers are facilitated through designated docking sections along the corridor. To rigorously address the system's optimization, we formulate it as a mixed-integer linear programming (MILP) problem on a time-expanded network. Subsequently, an inter-transit iterative heuristic with a problem-customized rolling method is developed within a bi-level framework to address the large-scale complexity. Its performance is validated through extensive numerical experiments, substantially compared to exact solutions obtained from the Cplex solver, showcasing an impressive average computation time savings of 49.7% with a minimal quality decrease of 0.18%. Through a real-world case study, Pareto optimality analysis underscores MET-CA's 24.4% average electricity savings and highlights its advantages in efficiency and flexibility over bus rapid transit and demand responsive transit in urban corridor areas.