Illinois Route 1 is a state highway in the U.S. state of Illinois. Running parallel to the Indiana border, it is also the longest state road, starting on the south side of Chicago as Halsted Street at an intersection with U.S. Route 12 and U.S. Route 20, south to a free ferry crossing to Kentucky at Cave-in-Rock on the Ohio River. This is a distance of 325.59mi.Route descriptionCave-in-Rock to BirdsIllinois Route 1 begins at the ferry dock for the Cave-in-Rock Ferry in the eponymous village of Cave-in-Rock along the Ohio River. A continuation of Kentucky's Route 91, IL 1 begins its journey in the Shawnee National Forest, leaving the village of Cave-in-Rock for the hamlet of Loves Crossing, where it meets the eastern terminus of IL 146. For the next 20mi, IL 1 winds north through the forest, reaching a junction with IL 13, which connects to Equality and Shawneetown. Further north, IL 1 remains a two-lane road when it junctions with IL 141 at the Gallatin - White county line. IL 1 soon reaches the village of Norris City, where it junctions with U.S. Route 45. Here, IL 1 turns northeast and bypasses the village.
