At least five people involved in an early morning, seven-car pile-up on I-75 have been charged with drunken driving, police said. The pedestrian who police believe started the chain of wrecks was also charged, Clayton County Police spokeswoman Officer Danielle Rosa said. “The pedestrian started walking into the interstate,” Rosa said. “That’s what kind of caused the seven-car pile-up.” The pedestrian, who was taken to a nearby hospital in critical condition, faces a pedestrian in roadway charge, police said.