Taxi owners won another round Monday in their fight against the city's efforts to turn its yellow cabs green. Saying that emissions- and mileage-related laws were only for Congress to make, U.S. District Court Judge Paul A. Crotty blocked a new set of city rules that would have allowed fleet companies to charge fuel-efficient cab drivers higher rental rates for their vehicles. The higher rates would provide a strong incentive for those companies to switch to only greener, hybrid vehicles and phase out old gas-guzzlers. Despite rejecting the plan, Judge Crotty still praised the city's intent in his ruling: "Increasing the number of hybrid taxicabs is an appropriate and important governmental priority." And though this is the second time Judge Crotty has struck down the city's attempts to convert its taxis to a more fuel-efficient fleet, New York City Law Department Counsel Michael Cardozo says the city's not giving up yet: "We do not believe that Congress intended to prohibit local governments from implementing incentive programs ... that encourage the purchase of environmentally friendly taxis. We are exploring our legal options."