Cal ARB Provides Additional Time For Some to Comply With Truck and Bus Regulation


The Truck and Bus Regulation was adopted in 2008 to significantly reduce toxic particulate matter and oxides of nitrogen emissions from existing diesel vehicles operating in California. It targeted approximately 1 million diesel trucks. The existing regulation requires nearly all heavier trucks to have filters to reduce PM emissions beginning January 1, 2012, and replacement of older trucks starting January 1, 2015. The regulation requires most heavy trucks in California to install soot filters or upgrade to newer models with filters by January 1, 2014, and that nearly all trucks have them installed by January 1, 2016. By January 1, 2023, all trucks and buses operating in most urban areas and in regions not meeting federal clean air standards will need 2010 or newer model year engines.

On Friday, April 25, 2014, the California Air Resources Board (ARB) issued a press release announcing that “today it adopted amendments to its Truck and Bus Regulation that will provide new flexible compliance options to owners of aging diesel fleets and recognize fleet owners that have made investments to comply, while also protecting air quality.” ARB confirmed that this will “provide additional regulatory flexibility to small fleets, lower use vehicles, and fleets in rural areas that have made substantial progress towards cleaner air.” It also confirmed that “[f]leets that have invested in cleaner, compliant equipment and trucks will be able to use credits longer and any vehicles retrofit by 2014 do not have to be replaced until 2023.”

The adopted amendments to the Truck and Bus Regulation include:

  • A longer phase-in period for diesel PM requirements for trucks that operate exclusively in certain rural areas with cleaner air
  • Additional time and incentive funding opportunities for small fleets
  • A new compliance option for owners who cannot currently afford compliance
  • Expansion of the low-use exemption and the construction truck extension
  • Recognition of fleet owners who have already complied by providing additional “useable life” for retrofit trucks and reducing near-term compliance requirements

Additional Resource: Los Angeles Times, Air quality regulators give truckers more time to meet smog standards (Apr. 25, 2014)