KINGSPORT - Northbound Interstate 81 near mile marker 50 is completely closed due to a motor vehicle accident. Motorists should make every possible effort to plan an alternate route and avoid the area, so as to avoid unnecessary congestion and delays. Anyone already in the area is asked to obey all traffic instructions, exercise caution and patience, and drive with a heightened sense of awareness. According to the Kingsport Police Department, the crash is being investigated by the Tennessee Highway Patrol. The Tennessee Department of Transportation (TDOT) is in the process of setting up detours.