The federal government is barring states from allowing electric vehicles (EVs) and other clean cars to use carpool lanes without meeting vehicle occupancy requirements starting on October 1, California officials said on Wednesday.
California governor Gavin Newsom said single drivers with the state's clean air vehicle decal will no longer be able to use carpool lanes or receive reduced toll rates in some areas.
California and other states used the perk to incentivise the sale of EVs. President Donald Trump has taken aim at EVs on a number of fronts including signing legislation in June to bar California's EV sales mandates.
California has issued more than one-million decals since the programme was created and has been open recently to EV and plug-in hybrid owners under a programme previously authorised by the Federal Highway Administration.
"By taking away this programme, hundreds of thousands of California's drivers will pay the price. It's a lose-lose and we urge the federal government to retain this programme. This is a great programme for climate-conscious Californians," said California department of motor vehicles director Steve Gordon.
A transportation department (USDOT) spokesperson said Congress in 2021 under then president Joe Biden opted not to extend the deadline.
"USDOT is working with industry stakeholders to develop policy priorities that best speak to the needs of working-class Americans," the department said.
Trump signed legislation in July that ends $7,500 (R131,430) tax credits for buying or leasing new EVs on September 30, as well as a $4,000 (R70,090) used EV credit, that have helped juice green vehicle sales in recent years.
Congress has also been considering imposing new annual fees on EVs to pay for road repairs as they do not pay federal fuel taxes.
In July, the Trump administration told carmakers they face no fines for failures to meet fuel efficiency rules dating back to the 2022 model year under a law signed by Trump. The administration is making other changes that will save carmakers billions of dollars in purchasing credits from Tesla and others to meet earlier regulatory requirements.