Clean Truck Check (heavy-duty inspection & maintenance)

Why it exists

Senate Bill 210 directed CARB to build a statewide heavy-duty inspection and maintenance (HD I/M) rule. The Board adopted the regulation in December 2021; implementation has rolled out in phases since January 2023. The program combines periodic testing, remote screening, and enforcement so emissions controls on heavy trucks stay working on California roads.

What problem it targets

Heavy-duty diesels over 14,000 lb remain a large share of on-road NO_x and PM_2.5. Modern engines use aftertreatment (DPF, SCR, etc.). When those systems fail, emissions can spike. Clean Truck Check is designed to catch high emitters, require timely repairs, and level the playing field for compliant operators.

How it works

• Roadside screening and other monitoring to surface potential high-emitting vehicles.
• Structured reporting and compliance paths through the Clean Truck Check Vehicle Inspection System (CTC-VIS).
• Emissions testing performed by credentialed testers (the role this app’s directory is built to help you discover).

Scale of expected benefits

CARB has published high-level projections for when the program is fully implemented — for example, substantial NO_x and PM reductions and large public-health benefits. Treat these as planning-level figures from CARB’s materials, not guarantees; read the original write-up for context and footnotes.

Recent policy context

CARB notes that program requirements apply to covered vehicles operating in California, including vehicles registered elsewhere. Separately, EPA actions on the State Implementation Plan can affect how emissions credit is counted federally without necessarily changing roadside compliance obligations — see CARB’s explainer language on their About page.