Some California drivers are getting all steamed up that they have to share the carpool lanes with single-occupant hybrids, like the Toyota Prius and Honda Civic, under a new state program. Some of the complaints, of course, should be taken with a grain of salt. Said one fumer in an online discussion group: “These [drivers] barely go 65 mph and allow no one to pass them on the right… Talk about road rage!” It’s hard to feel much sympathy for someone whining about not being able to exceed the speed limit.

But I do think there’s reason to be concerned that extra hybrids in the HOV lanes may be slowing down carpools & buses. From the LA Times article:

“There’s not enough excess capacity to absorb the hybrids,” said James Moore, director of USC’s transportation engineering program. “I think the foreseeable outcome here is that the congestion advantage we traditionally attribute to [carpool] lanes will disappear.”

Promoting hybrids could help save fuel. But there’s plenty of reason to believe that—looking at overall efficiency of road transport—filling the HOV lanes with hybrids could do more harm than good. Seems to me that California was smart in limiting the number of hybrids allowed in the carpool lanes, and studying the effects before proceeding.