Automakers are waiting for a tangible demand before they commit their considerable resources away from gasoline cars and toward alternatively fueled vehicles. Governmental, commercial and private fleets have a compelling volume purchasing power and could supply that demand, according to the San Francisco Chronicle. Today, alternative fuel vehicles are primed for widespread commercial and private use. Green fleet initiatives would spark competition among all truck and heavy-duty vehicle manufacturers to be the first to fill those orders. Volume purchasing would multiply and accelerate the technology, bring down costs and spread alt-fuel vehicles swiftly from commercial fleets to average consumers. For-hire carriers, such as UPS, Federal Express and Yellow Roadway, in 2004 operated 675,000 trucks and about 6 million additional vehicles are owned by private commercial fleets such as Sysco, Wal-Mart, Halliburton and Frito-Lay. City, state and federal agencies, as well as universities, comprise just a fraction of America's 38,000 private fleets. The federal government itself maintains America's single largest fleet by far—about 600,000 vehicles—but has been largely negligent in following its own alternative-fuel guidelines, the San Francisco Chronicle reports. The mandate requires that 75 percent of all vehicle purchases by federal agencies use alternative fuels.