California Clean Truck Program: This is a set of regulations from the California Air Resources Board (CARB) aimed at reducing emissions from heavy-duty trucks. Vehicles must meet specific emission standards to operate legally within the state. These regulations cover truck models from certain years and require regular inspections.

Compliance with CARB Standards: Vehicles must have the proper emission systems in place (like DPF – Diesel Particulate Filters) and regularly pass emissions tests to comply with state law. The clean truck check ensures trucks are in good condition to meet these requirements.