California's heavy-duty trucks don't have to get smog-checked. Why that's about to change

California motorists have been getting their vehicles smog-checked for decades.

Now the state's truckers will have to do the same.

The California Air Resources Board voted Thursday to require medium- and heavy-duty trucks and busses to get regularly smog-checked, saying the 1 million or so rigs on California's roads are responsible for a major share of the state's smog problem.

"It's a great day in the San Joaquin Valley," said Tania Pacheco-Werner, a board member from the Fresno area. With Valley air among the worst in California, she said the smog-test requirement will give "families and children a chance to have better lives and better outcomes."

Air board officials said trucks represent just 3% of California's vehicles but account for about half of the NOx and particulate-matter emissions produced by the transportation sector. NOx and particulate-matter are key to the formation of smog, which can cause asthma and other ailments. Officials estimated that 145,000 trucks could fail their smog tests.

"That's a lot of trucks—I want to catch them as soon as possible," said board member Diane Takvorian. The requirement applies to vehicles over 14,000 pounds.

Environmentalists called it the biggest anti-pollution step taken by the air board in more than a decade—and long overdue. Cars have been getting smog-checked since 1984.

The board said the regulation will take 71 tons of NOx emissions out of the air each day by 2031, a reduction of 50%.

Trucking industry officials generally accepted the board's vote. But they warned that, as supply-chain woes continue to plague the American economy, truckers might struggle finding replacement parts to fix faulty emissions systems. And if they have to take their rigs off the road, it will worsen the supply issues for the economy as a whole.

"We're never going to solve the supply-chain crisis if the transportation providers themselves fall victim to these same problems," said Chris Shimoda of the California Trucking Association. "We can't cause a ton of downtime."

The requirement begins in 2023 in Southern California and the San Joaquin Valley. It goes statewide in 2024.

These smog-checks will look a lot different than what ordinary motorists undergo. Much of the emissions data will be recorded in real time by onboard diagnostic equipment. The trucks will have to undergo in-person inspections twice a year, although that requirement eventually will increase to four times a year.

Trucks are already subjected to occasional testing for pollution, but the inspections "don't catch all the pollution," said Bill Magavern of the Coalition for Clean Air.

The vote came two years after Gov. Gavin Newsom signed SB 210, which directed the board to develop a smog-check program for trucks.

Magavern recalled talking to Newsom about the bill while it was still in the Legislature, and the governor hadn't been aware that trucks weren't required to undergo smog checks.

"He was shocked to find that out," Magavern said. "A few months later, he signed the bill."

©2021 The Sacramento Bee.

Distributed by Tribune Content Agency, LLC.