Are hybrids officially swimming in the US mainstream? A recent federal government amendment appears to imply as much, since it says that hybrid drivers won't be able to count on getting solo access to high-occupancy-vehicle (HOV) lanes. And the Prius Nation sighs.

A recently approved six-year highway-spending bill includes an amendment sponsored by Sen. James Inhofe (R-OK) that would forbid states from creating new HOV-access programs for solo drivers in hybrids. States with existing programs, like Virginia, would be allowed to continue them. Plug-in hybrids, extended-range plug-in vehicles and battery-electric vehicles are safe, The Detroit News says. Heck, even compressed natural gas (CNG) and hydrogen fuel cell vehicles will be able to continue to join the lonley party. For now.

Of course, hybrids-as-mainstream vehicles is old news to states such as California, long a leader in the advanced-powertrain vehicle movement. The Golden State gave out 85,000 yellow stickers that permitted hybrid drivers access to the HOV lanes no matter how many people were in the car, but they all expired in July 2011. After a slow start, California ran out of stickers that let plug-in hybrid drivers do the same earlier this year. California set a limit of 40,000 of those green stickers, which give drivers solo diamond-lane privileges through the end of 2018. The state has no limit on the number of stickers set aside for battery-electric vehicles which, like the green stickers, expire at the start of 2019.

Americans bought about 450,000 non-plug-in hybrids last year, including about 222,000 non-plug-in Toyota Prius models.