Lots of trends start in California.  Some of them are good—like the state’s clean car standards (now under consideration in Washington State) and its  vehicle global Warming law.

But some trends aren’t so good. The latest in the "not so good" category is the national push to let states open up their HOV lanes to hybrid vehicles. California did it a while back, opening up HOV lanes to any hybrid that gets at least 45 mpg. Now federal legislators have introduced a bill to allow all states to do the same thing

As I’ve said before, I think this could be a mistake.

  • My reservation about opening up HOV lanes to hybrids isn’t because I don’t like hybrids. I do;  I like them a lot, and I wish I owned one. (But, at the same time, I recognize that in many cases, some of the benefits hybrids provide—cleaner air, lower climate-warming emissions, less fossil-fuel dependence—can often be attained at a lower cost.)

    Instead, I’m concerned because, from a fuel-efficiency standpoint, giving more and more cars access to HOV lanes could be counterproductive.

    To me, one of the biggest benefits of HOV lanes in many urban areas is that they provide a relatively unobstructed lane for buses and vanpools—which, if reasonably full, are far more fuel efficient than hybrids. That’s certainly true in Seattle—the bus system is fairly widely used druing rush hour in greater Seattle, in part because the HOV lanes make bus trips a relatively convenient option for many commuters.

    Filling up the HOV lanes with hybrids could make traffic on HOV lanes more congested—thereby reducing the appeal of a bus trip. If more people opt for a car (even an efficient one) rather than the bus for their morning commute, then that more than offsets the benefit of opening up HOV lanes to hybrids. The worry isn’t just theoretical: Virginia has opened up carpool lanes to hybrids, and carpoolers have already begun to complain about bumper to bumper traffic.

    Over the short term, though, that’s probably not much of a problem in the Northwest. There just aren’t that many hybrids on the road. But once a benefit is put in place, it’s hard to revoke. So ten years down the road, when a significant share of the cars on the nation’s highways are hybrds, HOV lanes could very well be clogged by solo drivers who consider the free use of the carpool lanes a right, rather than a privelege. And when those lanes are clogged, not only will bus traffic slow down, but the HOV-lane privilege will cease being much of an incentive for prospective car buyers to choose a hybrid in the first place.

    Now, California did right for itself by limiting HOV access to no more than 75,000 hybrids, first-come, first-serve. And it limited access to cars that get 45 mpg or more—which would likely exclude American-made hybrid SUVs, such as the Ford Escape. Both provisions help to ensure that the law doesn’t clog HOV lanes too badly, or open up the HOV lanes to low-mileage vehicles.

    But my guess is that the national bill will have no such limits—Ford’s lobbying power is stronger in DC than it is in Sacramento. Some federal legislators already want to open up HOV lanes to any hybrid whose mileage is 10% better than a comparable vehicle—meaning, perhaps, that states could let a hybrid hummer that gets 13.2 miles per gallon, instead of 12, in the HOV lanes. Even if the law doesn’t start out stupid, it’s likely to get that way as it bubbles through Congress, or is amended in future years.

    Over the long run, letting hybrids clog bus and vanpool lanes could increase, rather than decrease, rush-hour fuel consumption. To me, that means that before we enshrine this idea in law, it would be much wiser to wait and see how the California and Virginia experiments go. Hybrid sales are in overdrive already; at this point, holding off on opening up HOV lanes won’t do much of anything to slow them down.