Starting with a short section at N. Canal and W. Lake Streets, it begins in earnest at the corner of N Desplaines and W. Kinzie Streets and heads northwest for about 40 miles before joining Skokie Highway (U.S. Route 41) in Gurnee, Illinois, which eventually merges at Interstate 94 where Skokie Highway and the Tri-State Tollway split off, continuing to Milwaukee.