Optimal design of sustainable transit systems in congested urban networks: A macroscopic approach

Mass transit is a key component of a sustainable transportation system in urban networks. In this research, we propose a continuum approximation model to optimize the line spacing, stop spacing, headway, and fare of the transit system by minimizing a linear combination of (1) users generalized cost, (2) agency operating cost, and (3) external cost of the emission in the urban region. The design of the transit system can be optimized by minimizing the total cost of the transportation system in three different network allocation scenarios: (i) mixed network (Bus), (ii) dedicated lanes (BRT), and (iii) parallel networks (Metro).