California air regulators approve landmark zero-emission rules for trucks and locomotives

In perhaps the most consequential session of the year, California air regulators have adopted two landmark rules setting aggressive zero-emission requirements for fleets of heavier vehicles and locomotives, a move expected to drastically cut pollution near ports and rail yards and alter the way goods move through the American West.

In a marathon two-day hearing, the California Air Resources Board voted to set an age limit to retire old locomotives while establishing a regulatory framework that requires operators to set aside money to upgrade to cleaner engines and eventually zero-emission powertrains.

In a second vote Friday, the board enacted a rule that will accelerate the adoption of zero-emission medium- and heavy-duty vehicles in all public and