PHOENIX — Ford and General Motors, two major suppliers of vehicles that run on compressed natural gas (CNG) and propane, are discontinuing production of some models after the 2004-model year to focus on gas/electric hybrid vehicles and hydrogen-fuel research. This leaves government fleets in Arizona and elsewhere scrambling to meet air-quality goals, reports The Arizona Republic, as reported by Weststart-CALSTART on August 19. Federal law requires state governments to buy alternative-fuel vehicles, and Arizona state law says that at least 75 percent of government fleets in urban areas must run on clean-burning fuel, although there are no penalties for non-compliance. "We're at a critical juncture in alternative fuel," said Mark Leonard, Phoenix public works director. The state statute "is not achievable now and will become even less achievable." Market forces also prompted the demise of CNG and propane vehicles, said Joanne Krell of GM's environmental and safety group, noting that sales of the alternative-fuel vehicles have dropped off. Public acceptance of natural-gas vehicles has been tepid, even among dedicated environmentalists, mainly because of the limited sources for refueling vehicles. The recent advances in hybrids and upcoming clean-diesel initiatives also have pushed back natural gas and propane. "We tend to do what the market wants to buy," Krell said. "In the long term, we really believe hydrogen is the answer," she added. The cities and agencies that use natural-gas or propane vehicles can continue using them as long as they run, but after the vehicles are retired, there will be no replacements available. Phoenix officials have hired consultants to study the situation, Leonard said, and in the fall, expect to hear a report from them, which will help them decide which direction to go. "What we're doing now is stepping back and looking at the entire approach to alternative fuel," he said.