Illinois Route 255 serves as a northern extension of Interstate 255 in the Metro-East (the Illinois portion of the St. Louis metropolitan area). Though an Interstate designation hasn't been approved for this section of road north of Interstate 270, the state route is a freeway for all of its length. Illinois 255 is a handy freeway bypass of the Alton area to the east, connecting Illinois's US Route 67 corridor to the Metro-East and points south.
The northern beginning of Illinois 255 is a split off of US Route 67, which continues into Alton:
The northern beginning of Illinois 255 is a split off of US Route 67, which continues into Alton:
Illinois 111, which follows parallel with Illinois 255 in this region, has an interchange with Illinois 255:
Illinois 255 has a full interchange with Illinois 143, that served as the former northern endpoint of Illinois 255 before the latest segment was completed:
The southern end of Illinois 255 is its transition into Interstate 255 at Interstate 270.
