California's Air Resources Board Mandates Zero Emission Buses

California’s Air Resources Board voted Friday to require public transit agencies throughout the state to commit to buying only zero-emission buses starting in 2029, a policy that boosts manufacturers including Proterra Inc. and China’s BYD Co.

The Innovative Clean Transit rule will force California’s public bus lines, many of which now run on diesel or natural gas, to shift to electric power or hydrogen fuel cells. The measure assumes the state’s bus fleet will turn over to zero-emission vehicles by 2040. Friday’s vote came after nearly three years of discussion and input from transit agencies, industry and public-health groups.