Rules that effectively require electric-car production in California stayed on the books after air regulators deadlocked over how to switch their focus to fuel-cell vehicles that are years away from rolling off the assembly line, Associated Press (AP) reported. AP said the state’s Air Resources Board could not reach a decision Mar. 28 on changing its zero emissions vehicle rule after members of the public and many interest groups urged it not to abandon the strict quota for clean cars it set 13 years ago. The board planned to revisit the issue in April. According to AP, the board has consistently worn down the rule it passed in 1990, which would have required 10 percent of cars sold in California this year to be pollution-free. The first-in-the nation regulation has helped inspire cleaner technologies including hybrid gasoline-electric vehicles and cleaner gasoline-burning cars. AP said the latest proposed revision was prompted after a federal judge in Fresno sided with Detroit car makers and put the quota on hold last year. The state would continue to push for cleaner technologies under the proposed rule, and would require car makers to put 250 nonpolluting fuel cell vehicles on the road in the next five years, AP said. One of environmentalists' chief concerns with the proposed rule was that it would not force car makers to build any zero emission cars after 2009, Associated Press said.