Arizona is facing a major budget crisis because of a well-intentioned but poorly designed law that gives residents big incentives and tax breaks for buying vehicles that run on alternative fuels. The program was expected to cost between $3 million and $10 million, but so many residents have taken advantage of it that it is now expected to cost at least $420 million, about 7 percent of the state’s $6 billion annual budget. Arizona Gov. Jane Hull (R) has called a special legislative session beginning today to put the brakes on the runaway program. At least lots of Arizonans are now driving eco-friendly cars, right? Well, no. Nearly 90 percent of the people who have applied for the credits bought vehicles that can run on both gasoline and natural gas or propane, or had their old vehicles retrofitted with alternative fuel tanks, but there is no requirement that drivers actually use alternative fuels, and most probably aren’t.