The California Air Resources Board on June 25 unanimously adopted the first statewide zero-emission commercial truck requirement, the Advanced Clean Trucks rule.

The main component of the rule is an electric truck sales standard. Manufacturers who certify Class 2b-8 chassis or complete vehicles with combustion engines would be required to sell zero-emission trucks as an increasing percentage of their annual California sales from 2024 to 2035. 

By 2035, zero-emission truck/chassis sales would need to be 55% of Class 2b to Class 3 straight truck sales, 75% of Class 4 to Class 8 straight truck sales, and 40% of truck tractor sales. 

By 2045, every new truck sold in California will be zero-emission.

Trucks are the largest single source of air pollution from vehicles, responsible for 70% of the smog-causing pollution and 80% of carcinogenic diesel soot even though they number only 2 million among the 30 million registered vehicles in the state, according to CARB.

According to a press statement by CARB, the new requirement to shift to zero-emission trucks and cars will help California meet its climate goals and federal air quality standards, especially in the Los Angeles region and the San Joaquin Valley, which suffer the highest levels of air pollution in the nation.

New NOx Emissions Rules on the Way

In the coming months, CARB will also consider two complementary regulations to support this action, the organization stated.

The first sets a stringent new limit on NOx (oxides of nitrogen), one of the major precursors of smog. This will require that new trucks that still use fossil fuels include the most effective exhaust control technology during the transition to electric trucks. There is also a proposed requirement for larger fleets in the state to transition to electric trucks year over year.

Today’s action was preceded by multiple CARB regulations to transition to zero-emission passenger cars, cleaner diesel fuel and improved technologies to limit diesel emissions for all trucks and buses. Over the past few years, CARB has also set rules to electrify buses used by transit agencies and shuttles at the state’s largest airports by 2030.

Reactions to CARB Electric Trucks Rule Mixed

Environmental groups hailed the decision.

"Today California took a significant step forward, demonstrating how states can play a pivotal role in charting a new course for the country to protect public health while building the backbone of a cleaner, more equitable economy," said Patricio Portillo, transportation analyst with the Natural Resources Defense Council, in a statement.

However, during the public comment process, trucking and other groups expressed concern over the increased cost for the technology and unknowns over battery range and durability.

Trillium, Love’s alternative fuels business unit, said the rule “sets nearly impossible goals for deployment of currently non-existent heavy-duty vehicles as targets, falls short in optimizing emissions from non-zero-emissions vehicles, and excludes private enterprise from the infrastructure/refueling space altogether.

“In short, this rule picks unproven technologies as the way forward with no backup plan, and sets up no means for private enterprise to deliver on these lofty promises.” The Trillium letter said.

In an announcement sent out shortly before the CARB decision, the Diesel Technology Forum suggested that faster adoption of the latest clean-diesel technology could help meet air quality goals. In a statement, Forum Executive Director Allen Schaeffer said California's regulatory environment has resulted in fleets keeping older, higher emitting trucks on the road for longer, and that only 36% of registered diesel trucks in the state are of the newest generation diesel emissions technology, "falling short of the national average of 43%, and well behind Indiana where over 65% of all registered trucks are of the newest generation."

"Today, diesel engines using renewable diesel fuel and blends of biodiesel fuels in California are delivering more greenhouse gas benefits than all electric vehicles combined," he said. "The replacement of older trucks in California with more efficient new diesel models, coupled with the use of these biofuels, represents a low-cost solution to deliver substantial and immediate greenhouse gas reductions compared to other approaches."