Article Photos: Natural gas drillers target US truck, bus market 3/3

  In this Nov. 19, 2012 photo, Waste Management driver Alan Sadler fills his truck with CNG gas at the company's filling station in Washington, Pa. Years from now, motorists needing a fill-up might see natural gas pumps sharing space at the neighborhood filling station with ones dispensing gasoline and diesel. (AP Photo/Gene J. Puskar)