- California gives EVs and zero-emission vehicles access to the carpool lane, even if there’s only one person inside.
- The federal law that allows single-occupancy vehicles to use carpool lanes under certain circumstances is set to expire in September.
- If it does expire, the carpool lanes may go back to their original, better purpose: Encouraging carpooling, which is an easy, cost-effective way to reduce your carbon emissions.
California’s electric vehicle owners have long enjoyed a major perk. With a qualifying clean-air vehicle—which can include hydrogen cars—owners get access to the state’s faster-moving carpool lanes on interstates, even if they’re driving alone. But the expiration of a federal law in September may mark the end of this perk. To that I say: Good riddance.
Federal laws govern interstates, and one law allows states to give access to certain single-occupant vehicles. That’s what allows California to offer unrestricted access to clean-air vehicles, and Automotive News reports that it’s set to expire in September. There appears to be little appetite in Washington to extend it, given, well, everything.
California’s sprawling highways are still choked with traffic. Carpool lanes are a smart solution to that issue, but not if one in four cars can access them whenever they choose.
Climate-conscious readers worried about the state of the EV industry likely see this as yet another loss. I’ll offer the counterpoint. The incentive was created to spur EV adoption. It was a success. While high gas prices, aggressive CARB emissions requirements, generous state-level subsidies and a broadly climate-conscious population are all likely bigger factors, these sorts of perks helped California become America’s primary EV market.
Today, that market has matured. One in four new cars sold in California last year was a zero-emissions vehicle. That’s largely possible because of that $7,500 federal tax credit, which I still fully support. It’s the carpool access that no longer makes sense. “Currently, California has about 519,000 active stickers,” California Air Resources Board John Swanton, told The San Fransisco Chronicle earlier this year. “With more than 2 million cars sold in the state, it doesn’t seem that access to decals is a significant driver in purchase decisions.”
At this point, it’s not super clear it’s a big reason for people in California to go electric. The cost of this strategy, however, is making a tool far less useful for everyone else, and far less capable of solving the problem it was intended to solve.
California’s traffic issues are systemic, and cause a ton of harm. Not only do they waste time, but they also make existing ICE vehicles less efficient, increasing emissions. Since low-speed stop-and-start driving produces the most smog, it also worsens the air quality problems that persist in most of the state.
Driving EVs does reduce these burdens. But it doesn’t solve the economic problems with traffic-choked cities. It doesn’t solve the land-use issues that come up when you require so much parking and infrastructure. And even if your car isn’t belching toxins, its presence is slowing down commercial trucks, internal combustion vehicles and everyone else. Every car is a force multiplier on each other, and it all compounds.
Decades ago, California recognized the real solution. The only way to reduce traffic is to reduce the number of people driving places every morning. Big EVs can’t do that. Carpooling can. It’s a useful tool that is far more cost-effective and accessible to people than buying a brand-new EV.
To work, though, there needs to be a stacked incentive. Sure, I’d love to halve my gas bill heading to work, but not as much as I’d like to sleep on my own schedule, listen to my own music and generally commute without worrying about anyone else. We were all raised in an individualistic society, and we like our big metal isolation chambers.

This qualifies for a carpool lane access sticker. A regular Prius doesn’t.
But if carpooling halved the time you spent in traffic, you’d consider it, right? I know I would. Because then you are giving me time and money, just for a bit of a convenience penalty.
It’s a solid trade. The structural issue is that it relies on carpool lanes actually being faster. That’s not inherently true. In many cases, they aren’t. They’re clogged with Teslas and Mach-Es all ferrying nothing but a single driver.
In most cases, the carpool section is either one or two lanes, compared to four or so for the regular lanes. When one in four new cars gets automatic access to the lanes, and another chunk of people get access through carpooling, suddenly having two out of six lanes dedicated to carpooling doesn’t lead to a much less congested experience. Unless over one out of four highway lanes is dedicated to carpooling in most areas, there’s no clear benefit when there are this many qualifying vehicles.
I should note, too, that there’s no guarantee that kicking EVs out of the carpool lanes will solve all of these congestion issues. A study from the University of California Berkley found that when hybrids were kicked out of California carpool lanes back in 2011, the average speed in carpool lanes actually fell.
The study suggested that, as carpool lanes run alongside normal lanes, more crowded standard lanes reduce speeds in adjacent carpool lanes. You’re not going to drive 50 mph along traffic that’s only going 10. California has added more barriers separating some carpool lanes, and limited merging areas, but that problem may still dampen the ability for carpool lanes to be that much faster.
That leaves us with only two not-great options. You can turn them into standard lanes—giving up on the idea that priority lanes can be meaningfully faster. One study, for instance, found that as carpool lanes expanded the number of people actually carpooling still decreased. Maybe we give it up.
The other option is to reduce the number of vehicles in the carpool lanes to actually incentivize better commuting behavior. You can’t remove access for carpoolers. That’s what these lanes are for. But you can remove preferential treatment for, potentially, single occupants who just happen to be in EVs and FCEVs. So if that law doesn’t get extended, and carpool lanes go back to being for carpools only, that’s a net win for the climate and the state.
I’d rather see four people commuting to work in a Camry together than one guy driving a Cybertruck alone.
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