California is far and away the country’s largest adopter of plug-in electric vehicles. Because of the state’s ability to regulate its own air quality and spurred on by a large economy and plenty of affluent residents, the EV has gained plenty of traction in the Golden State. So much so that last month, California met its goal of having more than 1.5 million clean vehicles on the road two years ahead of schedule.

“No other state in the nation is doing as much as we are to accelerate our electric and zero emissions future,” said California Governor Gavin Newsom. “California is setting the bar for climate action—and we’re achieving our goals years ahead of schedule thanks to unprecedented investments secured in partnership with the legislature. We’re making real progress on the world’s most ambitious plan to end the tailpipe so our kids and grandkids are left with a cleaner, healthier planet.”

California’s Air Resources Board (CARB) began its Zero-Emission Vehicle (ZEV) program in 1990 with the intent of ameliorating the state’s severe smog problem. By the early years of this century, air quality had improved to the point where CARB could begin using the ZEV regulations to help drive down climate emissions.