Illinois State Route 255 is a extention of Interstate 255. Prior to October, 2006 it ran from Interstate 255/270, near Pontoon Beach to Illinois State Route 143, near Wood River. On October 20, 2006, the 7.6 mile extention was opened. This extended to Fosterburg Road, at Alton. All truckes must exit at Illinois State Route 111/140. The eventual plan is for the highway to be extened to U.S. Rt. 67. Then U.S. Rt. 67 would be widened to Jacksonville. Creating a expressway from Jacksonville to St. Louis. IL St Rt 255 passes through the following towns in Madison County. Edwardsville Roxana Bethalto Alton IL St Rt 255 is not multi-plexed in Madison County. IL St Rt 255 intersects the following highways in Madison County. Interstate 255, at Pontoon Beach. Interstate 270, at Pontoon Beach. Illinois State Route 143, at Roxana.