California passes most stringent diesel-engine emissions rules: ‘Fighting for air’

State to implement most ambitious US regulations on railways, including phasing out locomotive engines over 23 years old

California has passed stringent new rules to limit emissions from diesel-fueled locomotive engines, putting the state on track to implement the most ambitious regulations on high-polluting railways in the country.

The landmark step taken by the California Air Resources Board (Carb), which regulates California's air quality, requires the phase-out of inefficient locomotive engines more than 23 years old by 2030, increase the use of zero-emissions technology to transport freight from ports and throughout rail yards, and bans diesel-spewing engines from idling for longer than 30 minutes.