Semi Jackknifes Across Highway, Blocking All Lanes as Cars Slide to a Stop Midwest Interstate — A terrifying chain of events unfolded on a busy highway when a semi-truck suddenly jackknifed across multiple lanes, blocking traffic completely and forcing nearby drivers into evasive maneuvers as tires screeched and vehicles skidded to a halt. Dashcam footage shows the tractor-trailer beginning to lose control as its trailer swings sharply to the left, rotating across the roadway. Within seconds, th