Interstate 255 (I-255) is a highway in the United States that serves as a bypass around the city of St. Louis, Missouri. It connects Interstate 55 and Interstate 70, providing an important route for traffic traveling in and out of the metropolitan area. The highway spans approximately 20 miles and is primarily located in Illinois. I-255 was completed in the late 1970s and is designed to facilitate regional travel and commerce. It features several interchanges that connect to local roads and other highways, making it a vital part of the transportation network in the region. The highway is also known for its scenic views of the Mississippi River.