Arizona is the latest state to offer up high-occupancy vehicle lane access to hybrid car drivers. If California's and Virginia's HOV lane experiments are any indicator, it may lead to a localized form of global warming—existing HOV lane users who are annoyed at the additional congestion caused by single-passenger hybrids clogging HOV lanes.

Arizona Governor Janet Napolitano authorized access to HOV lines (which otherwise would require two or more occupants) for up to 10,000 hybrids that attain a 45 percent increase in efficiency over comparable vehicles. That limits eligible vehicles to three: the Honda Insight and Civic Hybrid, along with the hybrid best-seller Toyota Prius (pictured). Arizona has an estimated 9,000 hybrids now; the permits are on a first-come, first-serve basis.

In California, access to HOV lanes did spur sales of hybrids, partly by some motorists who were about to buy a new car anyhow and jumped at the chance to get a tax refund for buying a hybrid and also to drive solo in carpool lanes. Napolitano said, "Drivers who make the commitment to clear air and energy efficiency will get an easier commute. That seems like a good trade to me."

What remains to be seen is whether Arizona's HOV lanes can handle the increased traffic flow, especially in Phoenix—America's ninth-largest city. Both California and Virginia capped the number of hybrid permits, but some critics say the cap was too high and the states didn't calculate the time and energy wasted by other motorists with now-longer commutes.

If the debate is fascinating to you, we can't recommend too highly a thread on the topic in the Arizona Republic's online edition [[http://www.azcentral.com/news/articles/0209hybrids0209online.html]] ("Laura, if you were hott [sic] I would excuse the last remark … go hug a tree and smoke a bowl" and "Do you Republican morons have nothing else better to do than troll blogs?").