California regulators on Friday approved new rules requiring all medium- and heavy-duty vehicles sold in the state in 2036 be zero-emission, a day after the California Air Resources Board (CARB) adopted reduced emission regulations for locomotives.

“With these actions requiring all new heavy-duty truck sales to be zero emission and tackling train pollution in our state, we’re one step closer to achieving healthier neighborhoods and cleaner air for all Californians,” said Governor Gavin Newsom.

The rule also require transitioning existing fleets to zero-emission vehicles. Big rigs, local delivery and government fleets must transition to zero emission by 2035, garbage trucks and local buses by 2039, and sleeper cab tractors and specialty vehicles by 2042.

The board estimates the reduced pollution from the truck rules would result in $26.6 billion in health savings from fewer asthma attacks, emergency room visits and respiratory illnesses, and save $48 billion in trucking operating costs.

American Trucking Associations Chief Executive Chris Spear criticized the decision to force motor carriers to purchase zero-emission vehicles.

“California is setting unrealistic targets and unachievable timelines that will undoubtedly lead to higher prices for the goods and services delivered to the state and fewer options for consumers,” Spear said.

CARB said fleet owners can receive exemptions based on available technology to ensure they can replace older polluting trucks with ones that have the cleanest engines in the nation