A street sign marks the interchange of Interstate 40 and the Kilpatrick Turnpike. (Photo by Kyle Phillips/For Oklahoma Voice)OKLAHOMA CITY – An anti-turnpike group has sued the Oklahoma Turnpike Authority and four federal agencies, asking a judge to stop a portion of a massive toll road expansion and improvement project. Pike Off, a nonprofit citizen-led organization, filed suit last week in the U.S. District Court for the Western District, alle…