You've seen those cars with the HOV access stickers cruising down the carpool lane with only a driver inside -- their time is almost up.
John O'Dell has been covering green and alternative fuel cars for over 20 years, first at the Los Angeles Times, then at Edumunds.com. He now operates his own information site, GreenCarGuy.com.
"There are about 235,000 stickers, green and white, that have been issued prior to Jan. 1, 2017, and they all become null and void, Jan. 1, 2019," said O'Dell.
All the green stickers and white stickers expire. There is no way to renew or extend them.
"It's a bummer," said Megan Jorgensen of Costa Mesa.
She has the green sticker on her 2013 Ford C-Max Energi plug-in hybrid. Understandably, she's not happy.
"It was a huge motivator for us when we purchased our vehicle. And, I think, the stickers should be for the life of the vehicle," she added.
That's probably what a lot of people assumed.
It's still good news for owners of newer alternative fuel vehicles, sold after Jan. 1, 2017. Their red HOV stickers will still be valid.
"The problem is that there are 235,000 cars that can drive in the carpool lane with only one person in them. And that has created some issues, and that's one of the reasons the state decided to do this," said O'Dell.
Those carpool lanes were just getting too crowded, and the state wants newer, cleaner cars on the road. There will be a different sticker issued beginning Jan. 1, 2019. Those and the red stickers will expire after the fourth calendar year of issuance.
So what should you do if you've enjoyed carpool lane access but your decal is expiring?
You can buy a new, qualifying alternative fuel vehicle. The 2019 Chevy Volt qualifies, for example, though GM has announced that they'll stop building the Volt next year. Many other new cars qualify, too, but most are pricey, especially if people weren't planning on trading up just yet.
Or, you could buy a used alternative fuel car -- that qualifies -- from out of state. As long as it's never had a California sticker before, it's eligible for one of the new ones.
"Bring it into the state of California, and even if it had a sticker from the state it was first sold in, that doesn't count as far as California is concerned," O'Dell added.
But if you have a car with a white sticker or green sticker, as of New Year's Day, you're back in the other lanes of the freeway.