CARB passes “smog check” regulation for heavy-duty trucks and buses

10 December 2021

The California Air Resources Board (CARB) approved a ‘smog check’ regulation for medium- and heavy-duty trucks and buses with a gross vehicle weight rating (GVWR) greater than 14,000 lbs. A part of the program is the implementation of a network of remote emission sensors in the state.

The action will cover roughly 1 million heavy-duty trucks and buses operating in California. The vehicles are to be tested twice a year. CARB also directed a four-times per year testing frequency for trucks with on-board diagnostics to be phased in over time.

The program implements California Senate Bill (SB) 210 (Leyva; Chapter 298, Statutes of 2019), directing CARB to develop and implement a new, comprehensive Heavy-Duty Inspection and Maintenance program to control emissions more effectively from non-gasoline on-road heavy-duty vehicles. It will also include independent owner/operators who were exempt from the current program of periodic smoke inspections.

The program will require vehicles with a GVWR > 14,000 lbs operating in California to perform periodic testing and submit the data to CARB. Heavy-duty vehicle owners will be able to complete the required test and deliver the information remotely without having to travel to a testing location. For telematics users, an onboard diagnostics (OBD) inspection that draws emissions control performance data from the vehicle’s internal computer can be completed automatically without taking the vehicle out of operation. OBD systems have been required by CARB on heavy-duty vehicles since 2013. Older heavy-duty vehicles without OBD systems will continue the current opacity testing requirements with an added visual testing component.

The Heavy-Duty Inspection and Maintenance program will also roll out a statewide network of roadside emissions monitoring devices (REMD) and an automated license plate recognition camera network to screen for high emitting trucks, starting with the San Joaquin Valley and South Coast and expanding over time. The REMDs monitor vehicle emissions remotely. An REMD pilot program conducted in November 2020 in Mountain Pass, CA, using remote emission sensors by PEAQS, HEAT, and Opus, showed good correlation and repeatability for NOx emissions, CARB said.

All vehicles operating in California will be required to have a valid HD I/M compliance certificate to operate legally in the state. For in-state vehicles, HD I/M program compliance will be tied to the vehicle registration.

Source: CARB