Have a hybrid? Enjoying riding solo in the carpool lane? Those days could be numbered.

Some in California’s legislature are proposing new rules that would either grant solo driving privileges only to vehicles powered by alternative fuels like electricity and natural gas or would require hybrids to get at least 65 miles per gallon, rather than the 45 miles per gallon combined city-highway mileage required today. Why the changes? Too many hybrids.

Some form of carpool lane exemptions have been given to solo hybrid drivers in at least nine states—the others being Arizona, Colorado, Florida, New York, New Jersey, Tennessee, Utah, and Virginia. The perk is one of several incentives, including tax breaks, designed to boost sale of the energy efficient vehicles. And it looks like the incentives worked. There are over 85,000 hybrids in California alone, so many that the state maxed out two years ago on the number of stickers its program was permitted to distribute. “I live in Santa Monica, and you can't swing a dead cat here without hitting a Prius,” one Californian purportedly told the Monterey County Herald.

While many hybrids can meet the 45 mpg requirement, few on the market today could meet a 65 mpg bar. The current program—and the stickers—expire January 1st, 2011. Which is why lawmakers are beginning to debate what to do next. Part of the problem, says the Los Angeles Times, is that so many vehicles are using the carpool lane—and consequently clogging them up—that the state is in danger of using federal highway funds.

So what position should a dedicated greenie should take? On the one hand, if someone’s going to buy a car, you want to encourage them to get an alternative-fuel vehicle. On the other, you don’t really want to encourage the use of vehicles at all. According to the Sacramento Bee, green groups haven’t been advocating one side of the issue or other, but the paper noted that some have said that simply issuing more carpool lane stickers wouldn’t necessarily have an environmental benefit.

Of course, it’s also possible that these debates might prompt more people to consider using the carpool lane for what it was originally intended—carpooling!

Photo: billaday