That possibility has made California a national benchmark, because 19 of the 50 states in the American Union adopt some of its standards for light vehicles, and 11 follow its regulations for heavy units , which together represent the supervision of more than 40% of the light vehicle fleet and 25% of the heavy vehicle fleet in the United States.

This leadership has been sustained by the California Air Resources Board (CARB) , an agency that not only regulates but also invests millions of dollars in research to combat air pollution .

CARB has seven major regulations , including two that directly impact freight transportation: the Advanced Clean Trucks (ACT) regulation , which requires manufacturers and importers to progressively sell more zero-emission vehicles between 2024 and 2035, and the Advanced Clean Fleets (ACF) regulation , which requires certain operators to gradually upgrade their fleets to zero-emission vehicles between 2025 and 2042.

As Elizalde explained, the ACF has three criteria that must be met according to the fleet:

1. Local government fleets.

2. Haulage fleets (ports and railway yards).

3. Federal government and high-priority fleets.

CARB has decided to initially withdraw the request for an “exemption” from the third criterion, that is, “Federal Government and High Priority Fleets ,” which is the criterion that must be met by federal government transportation companies, private transportation companies that own more than 50 vehicles in circulation in California, or companies that use transportation services with sales greater than $50 million annually.

The enforcement of this regulation no longer carries penalties for non-compliance, Elizalde explained.

Consequently, that part of the regulation was put on hold , with no penalties for non-compliance. The rest of the regulation remains in effect for other sectors, but the overall balance has been altered.

The change represents a forced slowdown in electrification plans, especially for Mexican companies that operate directly in California or export units to that market, Elizalde noted.

“For Mexican transportation companies operating in California that met the high-priority fleet criteria , this decision represents a slowdown in the mandatory transition to zero-emission vehicles,” Elizalde explained.

He noted that these fleets are no longer required to meet the Zero Emission Vehicle (CEV) incorporation targets originally established in the ACF regulations.

“In practice, this means an indefinite extension of the deadline without specific goals, while the legal challenge filed by other states is resolved and the regulatory framework is redefined,” he said.

What impact does it have on Mexico?

Even for companies that don’t physically operate in California, the move has implications. Miguel Elizalde noted that many Mexican automakers sell units in that state under the ACT regulations, which remain in effect.

The problem now is that only the “supply” (manufacturers and importers) is regulated, while the “demand” (fleet operators) is partially unrestricted, Elizalde commented.

“This imbalance could lead to market distortions, and therefore, it would not be surprising if the provisions of the ACT were also reviewed or adjusted in the medium term, as its effectiveness depends largely on complementarity with the ACF,” he indicated.

The practical suspension of part of the regulatory framework threatens to weaken the comprehensive approach that sought to align the supply and demand for zero-emission vehicles in California.

Elizalde noted that these types of adjustments, although they may seem technical or distant, directly affected investment schedules, commercial strategies, and even industrial planning.

He also stressed that the suspension of the strictest part of the ACF had no set date for reactivation and could be extended for years, depending on the ongoing legal outcome.

In Mexico , where many companies had replicated or adapted their sustainability strategies based on California regulations, this pause represented, according to Elizalde, a turning point.

Beyond regulatory compliance, this presented an opportunity to rethink business models, redesign supply chains, and explore new technological opportunities.

For its part, CARB remains firm in its stance of protecting public health and reducing pollution. However, the regulatory landscape is no longer the same, and Mexican fleets (especially those with operations or interests in the U.S. market) are already closely analyzing the new scenario.

*Main image taken from the CARB website .

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El cargo California halts ACF rule; impact reaches Mexican fleets, warns specialist apareció primero en T21.