California Mandates Smog Checks for Heavy-Duty Trucks

Truckers will have to have their rigs smog-checked and certified in order to operate legally in California under a bill signed into law by the state’s governor, Gavin Newsom.

The measure, Senate Bill 210, makes California the first state with a smog-check program for medium- and heavy-duty trucks. It provides the industry a few years of relief before the smog checks begin, though. The estimated startup date for an operational program is 2023.

The law requires the state’s Air Resources Board to first plan and conduct a pilot program, then draft a full set of regulations. All trucks operating on California roads – not just those registered in the state – will be required to have smog-compliance certificates.


The board has up to two years after completing the pilot program to begin implementing a comprehensive smog-check program.

It will apply to Class 4 and heavier diesel trucks – those with gross vehicle weight ratings in excess of 14,000 pounds. It does not apply to gasoline-fueled vehicles.

Because it requires just smog checks, the measure won’t be affected by the battle over the federal government’s attempt to cancel California’s long-established power to set vehicle emissions standards that are tougher than federal limits.


“In the face of the White House’s inaction on climate change, California is stepping up and leading the way,” Newsom said. Friday’s bill signing was part of a broader package of actions aimed at improving air quality and reducing greenhouse gas emissions in the state.

Part of that package was the signing of a second measure, SB 44. It requires the Air Resources Board to develop a plan for cutting greenhouse gas emissions from Class 4 and heavier trucks. But that could be challenged by the expected lawsuit over the California emissions waiver.

Newsom also issued a “Climate Resiliency” executive order. It aims to leverage the state’s $700 billion in pension investments to promote less fossil fuel use and the adoption of “carbon-neutral” technologies.

That order also directs California agencies to consider greenhouse gases and emissions when acquiring new trucks and construction equipment.


State Sen. Connie Leyva, a Democrat from heavily smog-impacted San Bernardino County, introduced SB 210, the truck smog-check bill, earlier this year.

The county is the site of more than 5,000 warehouse and freight-distribution facilities, according to a recent report by the Southern California Association of Governments. Diesel trucks from the twin ports of Long Beach and Los Angeles drive to those facilities.

Heavy freight industry lobbying last year killed a previous effort by Leyva.


The California Trucking Association particularly objected to the absence of a limit on the fee for a smog-check certificate. The CTA took a neutral position after the bill was amended to cap the fee at $30 per certificate.

Heavy trucks account for more than 80 percent of the state’s smog-causing diesel particulate matter. They also produce nearly 60 percent of toxic NOx emissions, according to the air board. NOx, or oxides of nitrogen, is a byproduct of burning fossil fuels. Diesel is particularly rich in NOx.


The smog-check measure “means Californians will breathe easier,” said Bill Magavern, policy director for the Coalition for Clean Air.

The coalition and the American Lung Association in California were co-sponsors of the bill.

The air board estimates one-third of the Class 8 trucks registered in California don’t comply with current emissions rules.

The smog program will reduce NOx emissions by as much as 93,000 tons between 2023 and 2031, the board estimated. That’s the equivalent of taking 145,000 Class 8 trucks off the roads.

The measure “creates a level playing field for those operators who have taken the time and expense to comply with California’s emissions standards,” said Magavern.

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