California has unanimously approved its Advanced Clean Fleets rule which requires all new medium and heavy-duty vehicles sold or registered in California to be zero-emission by 2036, and will ban new diesel trucks from ports and railyards from next year.
The rule is an addition to the previous Advanced Clean Trucks rule adopted in 2020, and has been developed by the California Air Resources Board (CARB), which oversees all air pollution control efforts in California and maintains health-based air quality standards.
It’s a landmark move which – because of the size of California’s economy – is likely to have an impact around the world, not least because CARB estimates the new regulations will save $US26.5 billion in statewide health benefits from criteria pollutant emissions and net cost savings of $48 billion to fleets.
The new regulation applies to local, state and federal government vehicles as well as fleets owned by entities with annual revenues of $50 million or more that own, operate or direct at least one vehicle in California and have a total of 50 or more vehicles.
The new regulation affects medium and heavy-duty on-road vehicles with a gross vehicle weight of greater than 8,500 pounds (3,856 kg) as well as off-road yard tractors and light-duty mail and package delivery vehicles.
Diesel truck ban in Californian railyards and ports by 2035
Drayage fleets are short-hall trucks that connect freight between train, air and sea shipping ports.
The new regulation states that only zero-emission drayage trucks may register in the CARB system from January 1, 2024 and that although non-zero-emission “legacy” drayage tracks can continue to operate through their “minimum useful life”, all drayage trucks entering seaports and intermodal railyards are required to be zero-emission by 2035.
This is effectively a ban on the use of diesel truck fleets operating in Californian rail and sea shipping ports from 2035.
High priority and federal fleets must comply with the “Model Year Schedule” or may elect to use the optional ZEVMilestones Option (table below) to phase-in ZEVs into their fleets:
On high priority and federal fleets the new regulation states that if fleets choose to comply with the “Model Year Schedule” they must purchase only ZEVs from January 1, 2024 and that from January 1, 2025 fleets must remove ICE vehicles at the end of their useful life.
If operators choose the “ZEVMilestone” option they must meet ZEV targets as a percentage of the total fleet according to the table below.

For existing trucks CARB says “The proposed ACF regulation’s default Model Year Schedule begins in 2024, and allows drayage and high priority and federal fleets to continue using their existing trucks until the earlier of 18 years or 800,000 miles or a minimum of 13 years if the truck has over 800,000 miles.”
If operators choose the default Model Year Schedule however, only zero-emission drayage trucks may register in the CARB system from January 1, 2024 forcing them to start transitioning their fleets as soon as next year.
The new laws are promisingly aggressive with state and local agencies forced to purchase 50% ZEV by 2024 and 100% by 2027.
The default “Model Year Schedule” requirement all new drayage vehicle purchases to be 100% electric from the start of 2024 is to be commended in its ambition. The strength of such regulations is truly world leading.
New regulation set to accelerate electric truck uptake
California has a GDP of around $US3.6 trillion and is the the largest sub-national economy in the world. For context Australia’s GDP is around $US1.6 trillion.
Therefore any changes to regulations in California can have global ramifications as manufacturers are forced to retool to cater to the huge Californian market.
Since California introduced its Advanced Clean Trucks law in 2020, the proposed draft ACF has been strengthened because of increased awareness of the urgency to act on climate change and pollution.
The new 2036 target for an end to diesel truck sales was lowered from an earlier 2040 target to improve the chances of California achieving Governor Gavin Newsom’s goal for 100% zero-emission medium- and heavy-duty vehicles by 2045.
Since 2020 the market for electric trucks has also increased significantly with hundreds of total models available across every truck class. Range currently available in electric trucks is also more than enough to meet most fleet applications which often have predictable schedules.
The Californian Air Resources Board sys the new ACF regulation is expected to significantly increase the number of medium- and heavy-duty ZEVs on California roads, beyond the sales expected from the 2020 ACT regulation.
“The 2 regulations together are expected to result in about 510,000, 1,350,000 and 1,690,000 ZEVs in California in 2035, 2045, and 2050, respectively.” said CARB.

California’s new medium and heavy-duty 2036 ban on diesel trucks will come into force just one year after the state’s 2035 ban on new petrol and diesel car sales.