The California Air Resources Board (CARB) decided to require all newly purchased transit buses to be carbon-free by 2029, committing the state to phasing out all fossil fuel models from its 12,000 transit bus fleet by 2040. Electric and hydrogen fuel cell-powered buses are among those expected to replace diesel and natural gas models. A number of cities in California have already committed themselves to the phase-out, with Los Angeles and San Francisco setting target dates of 2030 and 2035, respectively.

The Freedonia Group’s global automotive and heavy equipment analyst Gleb Mytko assessed the significance of CARB’s decision: “Although California is already at the forefront of the shift to electric, hybrid, and other alternative fuel buses in the US, this move solidifies its commitment to reducing the environmental impact of the state’s public transportation system”. Many other states are expected to follow California’s lead in the future.

The distant target date for the phase-out attests to how much more is still left to be done. Currently, there are approximately 150 zero-emission transit buses in use in California, a tiny portion of the overall fleet. Gleb Mytko points out that “due to the high upfront cost of many electric and alternative fuel models, the state will have to allocate a large amount of public funds in order to fully phase out the use of fossil fuel buses by 2040.” The availability of high-quality, reliable electric and fuel cell will also have to increase for the transition to accelerate and California will have to invest heavily in developing an extensive network of charging stations.

The Freedonia Group, a division of, is a leading international industrial research company publishing more than 100 studies annually.