Integrated optimization of fleet sizing, deployment, and routing for electric service vehicles : case study STM

Abstract

The Société de transport de Montréal (STM), the public transport agency of Montreal, has committed to electrifying its entire vehicle fleet as part of its broader sustainability initiatives. This work addresses a critical challenge that arises from this commitment: optimizing the deployment and dispatching of electric service vehicles assigned to operations supervisors to ensure minimal disruption to the bus network. The problem is formulated as a mixed-integer linear program that minimizes the number of deployed vehicles and total response time using a lexicographic approach. The capacity of our model is evaluated through computational experiments using the commercial CPLEX optimization solver. This work provides the STM with a valuable strategic and operational decision-support tool, aimed at optimizing the size and deployment of its new electric vehicle fleet, while supporting its sustainability objectives.