A tractor-trailer accident in Roane County late yesterday jammed traffic on Interstate 40. Troopers say a 2015 Kenworth driven by Willie J. Butler of Colquitt, Georgia was heading west at the 343 mile marker when the rig started to hydroplane. The tractor-trailer then jackknifed and left the interstate. The tractor-trailer struck a guard rail, partially traveled down an embankment and came to rest on its side. Butler escaped injury in the accident.