Original title: Bus Fleet Electrification Under Capital Cost and Scheduling Constraints: A Five-Agency Case Study
Hadi Bhidya, Taner Cokyasar, Omer Verbas · August 2026
Cities want to replace diesel buses with battery electric buses, but electric buses need time to recharge. This means agencies cannot always trade one diesel bus for exactly one electric bus. Researchers tested how to replace them efficiently across five transit agencies. They built a planning model that figures out bus schedules, charging times, and the best fleet mix together. They found that the best fleets are mostly electric, but one diesel bus usually requires more than one electric bus to replace it. Replacement ratios ranged from 1.101 to 1.245 electric buses per diesel bus. Cities with denser bus networks need fewer extra buses than spread-out networks, partly due to non-revenue vehicle activity. Planners must account for these extra vehicles to avoid costly mistakes.
You run a small bakery with a delivery van that makes the rounds all day. You decide to switch to an electric van, but it needs to recharge for an hour after every few deliveries, so you end up needing a second van just to keep the schedule. In this paper, transit agencies face the same issue: switching from diesel to electric buses requires extra buses because the electric ones need charging time, so the replacement ratio is greater than one-to-one.
Transit agencies switching from diesel to electric buses may assume one-for-one replacement. This study of five agencies shows replacement ratios ranging from 1.10 to 1.25 — meaning 10 to 25 percent more electric buses are needed. Ignoring this can lead to budget shortfalls and route coverage gaps.
The study's findings are descriptive, not causal, meaning the observed replacement ratios may not hold under different operating conditions. It only examines five U.S. agencies, so results may not generalize to all transit systems. The model's assumptions about charging infrastructure and costs are not detailed in this abstract, and the role of non-revenue activity is hypothesized, not proven.
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Bus Fleet Electrification Under Capital Cost and Scheduling Constraints: A Five-Agency Case Study — Hadi Bhidya, Taner Cokyasar, Omer Verbas
Abstract licence: CC0
Explanation generated by Synthesis from the abstract — it is not the original paper. This is a preprint, so it hasn't necessarily been peer reviewed.