The Owner-Operator Independent Drivers Association (OOIDA) has filed a lawsuit against the California Air Resources Board (CARB) over a requirement that older trucks be retrofitted with a particulate matter filter to operate in the state.

The lawsuit alleges that the regulation violates the Commerce Clause of the U.S. Constitution and discriminates against truckers from out of state. Furthermore, OOIDA argues that the regulation regarding particulate matter filters will "not result in any measurable global climate change, nor in any measurable reduction of the effects of global warming.” The rule in question takes effect January 1, 2014 for fleets with three or fewer trucks, though enforcement has been delayed until January 31 for owners making a "good faith” effort to comply.