The incident happened about 8:30 p.m. Wednesday on Interstate 57, about six miles south of Marion.
Kent Cook was flying a private aircraft when engine trouble developed. He guided the single-engine plane onto the I-57 median near milepost 47 in Williamson County, according to the Illinois State Police district based in Du Quoin.
The plane, a 1958 Cessna 175 Skylark, sustained minimal damage. Cook was the only occupant.
"It was the best possible outcome," he said Thursday.
Cook said he was flying from Union City, Tenn., to Lincoln. He was transporting the plane as part of his business, Kilo Aviation.
The company is based at Marshall County Airport in Lacon. It manages anywhere from four to 12 private planes.