The California Air Resources Board (CARB) staff will host a public workshop on 11 February to discuss ideas and strategies to reduce in-use emissions from heavy-duty diesel vehicles operating in the State of California. The objective of the workshop is to solicit stakeholder ideas and comments about potential strategies to ensure heavy-duty vehicles operating in California are well-maintained and have properly functioning emissions control systems.

The workshop will begin with an overview of the various strategies currently being utilized to reduce emissions from heavy-duty vehicles, and will include a discussion of concepts that could be implemented now and in the near future.

Staff will not present a draft program proposal at the workshop; instead, the majority of the workshop time will be used to allow participants to present their ideas to reduce in-use heavy-duty vehicle emissions.

Staff is particularly interested in hearing stakeholder concepts for a future heavy-duty vehicle inspection and maintenance (HD I/M) program.

The workshop will be held at the Cal/EPA Headquarters Building in Sacramento, California.

Background. To accelerate the adoption of the cleanest technologies, CARB adopted the Truck and Bus Regulation, which requires fleet owners to replace older engines with cleaner engine technology over time.

Even with these regulatory programs in place, heavy-duty diesel vehicles with a gross vehicle weight rating (GVWR) above 14,000 pounds are still one of the largest sources of air pollution in California. 2019 estimates indicate that these vehicles contribute approximately 58% of the statewide on-road mobile source NO_x emissions and about 82% of the statewide on-road mobile source particulate matter (PM_2.5) emissions.

CARB’s current inspection programs include the roadside Heavy-Duty Vehicle Inspection Program (HDVIP) and the fleet Periodic Smoke Inspection Program (PSIP). These regulations require heavy-duty vehicles operating in California to be inspected for excessive smoke and tampering. In July 2018, CARB approved amendments to HDVIP and PSIP to reduce the smoke opacity limits to levels more appropriate for today’s modern engine technology.

However, HDVIP and PSIP only require control of excessive smoke emissions and not other pollutants of concern such as NO_x and greenhouse gases. Consequently, CARB staff is seeking to engage in an open dialogue with interested stakeholders to identify potential strategies that would ensure that all heavy-duty in-use vehicles operating in California always meet the emissions requirements established by law and regulation, and to meet commitments outlined in CARB’s State Strategy for the State Implementation Plan.