The San Joaquin Valley Transit Electrification Project aimed to accelerate the deployment of heavy-duty, zero-emission public transit buses in disadvantaged communities across the San Joaquin Valley. This regional-scale effort demonstrated that California-made, battery-electric buses can effectively meet transit needs, significantly reduce greenhouse gas emissions, and eliminate harmful air pollutants—providing critical public health benefits in one of the state’s most air-quality challenged regions. The project’s scale helped lower per-vehicle costs and created opportunities for shared infrastructure, workforce training, spare parts, and maintenance resources. It stands as a successful regional model, offering scalable lessons to guide and educate other transit agencies. These insights support broader adoption of zero-emission technologies across California’s transit sector.