Equity-aware optimization for urban transit decarbonization: Modeling and case study

Achieving net-zero public transport systems requires the decarbonization of bus fleets. Transition plans prioritizing financial optimality may result in imbalanced resource deployment, leading to inequities within and across communities. This work proposes a composite spatial index for quantifying equity in transit system decarbonization. It also presents a multi-objective equity-aware optimization model for long-term fleet transition planning. The model jointly determines
fleet replacement and deployment over routes to minimize the transition costs while accounting for equity in decision-making. A case study is conducted based on the Metro Vancouver bus network using real-world data. The equity-aware model is assessed and compared with a financially optimal planning strategy. The results indicate that the proposed method can significantly mitigate inequities across communities during the net-zero transition, requiring only
minimal additional investment.