Electric cars: Advancing the deadline was a prudent move to avoid disappointment with the new vehicles and higher costs.

The decision last month by the California Air Resources Board to push back by five years the mandated introduction of zero-emission vehicles averts potential economic and environmental disasters. But other problems loom.

Based on our recent study, we believe that the board made a wise decision when it withdrew the requirement that 2% of California autos made from 1998 through 2000 and 5% from 2001 through 2002 be emission-free. Instead, the board received commitments by vehicle manufacturers to maintain their efforts to advance the technology. The wisdom of the board’s decision to keep its requirement that 10% of state cars made in 2003 and beyond be emission-free is harder to assess.

If the original mandate had remained, each electric vehicle sold before 2003 could have cost from $6,000 to $28,000 more to produce and operate over its lifetime than gasoline-powered vehicles. If current policies to control emissions from gasoline vehicles turn out to be effective, the electric vehicles would have displaced fairly clean vehicles.

Because the mandate linked electric vehicle sales requirements to gasoline vehicle sales, it could have boosted by several hundred dollars the price of new, cleaner gasoline-powered vehicles, slowed their sales and even caused overall vehicle emissions to increase in the short term.

The first crop of electric vehicles could have greatly disappointed consumers because of their limited range between battery recharges--generally under 90 miles, less if using air-conditioning or heating--and a scarcity of public charging stations. This could have greatly undermined the marketability of future electric vehicles, even if such limitations were overcome.

However, there were also great economic and environmental risks if the mandate had been totally scrapped. If electric vehicle technology stagnates and other efforts to control emissions are disappointing, California may have to turn to very costly and unpopular measures, such as mandatory car-pooling, to comply with federal clean air standards by 2010, the deadline for compliance in the South Coast Air Basin.

The board’s revision keeps the electric vehicle option open without pressing too hard, too soon. At the same time, by requiring manufacturers to field demonstration fleets of thousands of electric vehicles with advanced batteries and to maintain support for battery research, the new policy continues to promote the development of electric vehicle technology and reduces the possibility that we will forsake a clean air strategy that might eventually succeed.

The revision allows time to learn whether electric vehicles should be a cornerstone of California’s long-term clean air strategy. Experience will teach us about the potential of electric vehicle technology and about how consumers use and value electric vehicles. The change also provides the Air Resources Board with the flexibility to modify the electric vehicle program as new information becomes available.

But we would be wise not to spend too much time admiring these accomplishments. California still doesn’t have a reliable and affordable means of cleaning up the dirtiest air in the country. If we don’t find a way, we’ll face another disaster--having to choose between enormous costs and dirty air. We could even wind up with both.

The ultimate success of California’s clean air efforts depends crucially on how the electric vehicle and other programs are designed and implemented.

Two programs to reduce engine emissions bear special attention. California’s still evolving plan to buy and scrap 75,000 older vehicles a year in Southern California is unprecedented. And the Smog Check II program toughens the historically problematic vehicle inspection and maintenance program. Either could be a major success or a major disappointment. It all depends on how they are implemented.

The scrappage program could induce people to bring older cars into the region to replace those purchased and scrapped. It could also generate strong incentives to delay the repair or normal scrapping of dirty vehicles and even to tamper with vehicles to make them dirtier. The new smog check program may do little to reduce fraud by smog check technicians. It could also exacerbate evasion, because vehicle owners would have to spend much more on repairs than under the old program.

The Air Resources Board and the public should pay careful attention to the design and implementation of these programs and monitor them closely, both to assess whether benefits are worth the costs and to determine how hard California should continue to push electric vehicles.