Heavy Duty Trucking Logo
MenuMENU
SearchSEARCH

New Law Will Smog-Check Class 4-8 Trucks in California

Even as the Trump Administration attempts to roll back California’s right to implement stricter-than-federal vehicle emission rules, the Golden State has acted to further choke off diesel emissions from trucks.

David Cullen
David Cullen[Former] Business/Washington Contributing Editor
Read David's Posts
September 24, 2019
New Law Will Smog-Check Class 4-8 Trucks in California

 

New law requires CARB “to provide mechanisms for out-of-state owners of heavy-duty vehicles to establish and verify [smog] compliance prior to entering the state.” 

Photo: Jim Park

4 min to read


Even as the Trump Administration attempts to roll back California’s right to implement stricter-than-federal vehicle emission rules, the Golden State has acted to further choke off diesel emissions from trucks.

A bill signed into law by Governor Gavin Newsome (D) on Sept. 20 takes away the exemption from smog-compliance testing that’s long been in place for all commercial vehicles operating in California with GVW rating above 14,000 pounds. Zero-emission and certain authorized emergency and military vehicles would remain exempt from smog checks.

Ad Loading...

Under the new “Clean Trucks, Clean Air” (SB210) law, after a two-year pilot is run to develop all the specifics, vehicle inspection and maintenance program for non-gasoline heavy-duty motor vehicles with GVW ratings above 14,000 pounds (Class 4 through 8) will be put in place to regularly measure the effectiveness of their emission controls to reduce the release of particulate matter and nitrous oxide (NOx) into the air.

The bill, among other things, would:

  • Prohibit the “operation of a heavy-duty vehicle on a public road in this state if that vehicle has an illuminated malfunction indicator light displaying a specified engine symbol, and would make a violation of this provision subject to a notice issued by an officer to correct the violation on the basis of its designation as a mechanical violation. The bill would specify that a violation of this requirement is a correctable violation if the correction is made, as specified.”

  • Prohibit “the operation of a heavy-duty vehicle in a manner resulting in the escape of visible smoke, except during active regeneration. The bill would specify that a violation of this requirement is a correctable violation if the correction is made, as specified.”

In addition, the bill limits the annual “cost for compliance” to $30. It also calls for creating a Truck Emission Check fund, with all the monies deposited within to be used for the regulatory purposes of the program.

“Just as car owners have to get their own personal cars ‘smog-checked’ every two years, so too should truck operators be required to maintain their emissions controls so that we can ensure long lasting air quality improvements here in California,” said Senator Connie M. Leyva (D-Chino), who introduced the bill, in a news release.

Ad Loading...

She added that the new law “reinforces California’s leadership on improving air quality and public health, while also leveling the playing field for law-abiding truck owners and operators in our state.” The latter remark reflects Sen. Leyva’s contention that those California based truck owners that “strive to meet our nation-leading air quality standards” can be at a competitive disadvantage with non-compliant vehicles, including many out-of-state trucks.

That’s why a provision of SB10 requires the California Air Resources Board, once the new inspection program is launched, “to provide mechanisms for out-of-state owners of heavy-duty vehicles to establish and verify [smog] compliance prior to entering the state.” 

As signed into law, SB201 will “certainly require big trucks be ‘smogged,’” Joe Rajkovacz, director of governmental affairs and communications for the Western States Trucking Association, told HDT.

“However,” he continued, “a lot of the details are really left up to CARB to iron out [during the two-year pilot] and as always, the ‘devil’s in the details.’  Those details may become clearer over the next two years, but in the end this law gives CARB carte blanc to really do whatever they want.  We think the ultimate cost has been downplayed versus the current required smoke test protocol.”

According to a pamphlet published by CARB, the state’s Heavy-Duty Vehicle Inspection program already tests trucks and buses with a GVWRs above 6,000 pounds for excessive smoke and tampering. These tests can be performed unannounced and include testing the vehicle’s rpm at idle and at maximum speed, placing a smoke-sensing meter just above or inside the vehicle’s exhaust pipe, checking the engine for visible signs of tampering, recording engine data, and ensuring the engine has the appropriate emission control label.

Ad Loading...

Nonetheless, CARB estimates that once implemented, the new heavy-duty inspection and maintenance program will, between the years 2023 and 2031, “remove 93,000 tons of NOx and 1,600 tons of PM 2.5, equivalent to taking 145,000 and 375,000 trucks off the roads in California.”

More Fleet Management

Illustration with fraud and cybersecurity images and the words "The Cyber Stop"
Fleet Managementby Ben WilkensFebruary 26, 2026

NMFTA Targets Freight Fraud and Telematics Supply Chain Risks

New carrier identity checks, industry resources, and telematics supply chain research aim to make freight fraud and cyber risks harder to exploit.

Read More →
Bobit Business Media logo displayed next to The Fleet Source logo on a white background, separated by a vertical line.
Fleet Managementby News/Media ReleaseFebruary 25, 2026

Bobit Business Media Expands Fleet Technology Platform with Acquisition of Roadz Partner Portfolio

Bobit Business Media has acquired key partner agreement assets from Roadz, expanding its role as a go-to-market partner for fleet technology providers and strengthening its digital sourcing capabilities.

Read More →
American Class 8 tractor-trailers.
Fleet Managementby News/Media ReleaseFebruary 24, 2026

ATRI Seeks Carrier Data for 2026 Operational Costs Report

The annual benchmarking study from ATRI adds year-over-year comparisons for repeat participants as fleets navigate shifting market conditions.

Read More →
Ad Loading...
Fleetworthy fleet management.
Fleet Managementby News/Media ReleaseFebruary 23, 2026

Fleetworthy Unifies Brands Under Single Banner to Streamline Fleet Readiness

Company consolidates Bestpass, Drivewyze and CPSuite into one platform aimed at reducing vendor complexity and controlling fleet costs

Read More →
Podcast thumbnail saying "Cargo Theft: Is Your Load Next?"
Fleet ManagementFebruary 23, 2026

Double Brokering, Phishing, and the Rise of Strategic Cargo Theft

Cargo theft has evolved from parking-lot break-ins to cyber-enabled strategic fraud. Here’s what fleets need to know.

Read More →
YouTube thumbnail with Scott Cornell, HDT Talks Trucking Logo, and the words, "Is Your Load Next?"
Safety & Complianceby Deborah LockridgeFebruary 20, 2026

The New Cargo Theft Playbook — And How Fleets Can Fight Back

Cargo theft has shifted from parking-lot break-ins to organized international schemes using double brokering, phishing, and even spoofing tracking signals. In this HDT Talks Trucking video podcast episode, cargo-theft investigator Scott Cornell explains what’s changed and what fleets need to do now.

Read More →
Ad Loading...
Daimler Truck North America Vice President David Carson
Fleet Managementby Jack RobertsFebruary 19, 2026

Capacity Overhang Begins to Clear, But Fleets Aren’t Ready to Spend 

Daimler Truck’s David Carson sees early signs of tightening capacity — yet buyers remain wary, extending trade cycles and resisting a pre-2027 emissions surge. 

Read More →
Map showing which states have bad freight bottlenecks
Fleet Managementby News/Media ReleaseFebruary 17, 2026

Chicago Interchange Overtakes Longstanding New Jersey Intersection as Worst Freight Bottleneck

The American Transportation Research Institute's annual analysis of truck speeds through congested interchanges yielded a new worst bottleneck this year.

Read More →
HDT Top 20 Products Award Logo
Fleet Managementby Deborah LockridgeFebruary 13, 2026

HDT Top 20 Products 2026: The New Tools, Technologies, and Ideas Shaping Trucking

From pricing intelligence and compliance tools to charging infrastructure, diagnostics, tires, and AI, HDT’s 2026 Top 20 Products recognize the new tools, technologies, and ideas heavy-duty trucking fleets are using to run their businesses.

Read More →
Ad Loading...
Graphic promoting the Disaster Preparation & Response Guide with a red guide cover, “Call for Experts” text, and Bobit Business Media logo.
Fleet Managementby News/Media ReleaseFebruary 13, 2026

Disaster Readiness Starts Before the Storm [Call for Experts]

Disasters don’t wait — and fleet operations can’t afford to either. The 2026 Disaster Response Guide is now accepting expert insights on preparedness, response, and recovery strategies.

Read More →