California v. Chao

Three California air quality management districts filed a complaint in federal district court in D.C. seeking a declaration that the National Highway Traffic Safety Administration preemption rule is invalid. They also filed a related petition for review in the D.C. Circuit challenging the U.S. Environmental Protection Agency's withdrawal of California's waiver. The district court case was not officially consolidated with similar cases brought by <a href="https://climatecasechart.com/case/california-v-chao/">California</a> and other states and by <a href="https://climatecasechart.com/case/environmental-defense-fund-v-chao/">environmental groups</a>, but parties have been filing the same documents in each docket, and the documents can be found on the California case's <a href="https://climatecasechart.com/case/california-v-chao/">page</a>.

South Coast Air Quality Management District and two other air quality management districts voluntarily dismissed their action challenging the preemption rule. Only the action brought by California and other states remains pending. Proceedings are currently stayed while the remaining plaintiffs and the federal defendants continue discussions regarding the status of the case.