Interstate 57 southbound between Dix and Mt. Vernon was closed to traffic for about a half hour Wednesday afternoon when a truck caught fire.
Firemen then spent more than three additional hours in cleanup where there was only one way traffic.
Jefferson Fire believes a wheel bearing locked up on the cab, starting the blaze that spread to the front four feet of the trailer.
The truck was hauling cornmeal.
It is owned by Roadworks of Marion.
The fire was first reported at 3:30, with cleanup continuing until after seven pm.
