Overview
Interstate 55 is a primary north–south highway in the U.S. Interstate network. Stretching roughly 964 miles (about 1,552 km), it connects the New Orleans metropolitan region in southeastern Louisiana with the city of Chicago in northeastern Illinois. Designed as a long-distance arterial route, I-55 supports both regional travel and interstate freight movement between the Gulf Coast and the American Midwest.
Route and characteristics
The route runs generally north–south and passes through six states: Louisiana, Mississippi, Tennessee, Arkansas, Missouri, and Illinois. Its termini are near LaPlace (just west of the New Orleans area) in the south and in Chicago to the north. The highway is mostly a divided, limited-access freeway and alternates between rural stretches and urban expressways as it approaches major cities.
Major cities and connections
- LaPlace / New Orleans area
- Jackson, Mississippi
- Memphis, Tennessee
- St. Louis, Missouri
- Springfield and Bloomington–Normal, Illinois
- Chicago, Illinois
I-55 links with numerous east–west routes and metropolitan networks, providing key interchanges that facilitate cross-country trucking and passenger travel.
History and development
The corridor was developed as part of the post‑war Interstate program authorized in the 1950s. Construction proceeded in segments over many years, often upgrading or paralleling existing U.S. highways. Portions of I-55 follow or supersede older alignments such as U.S. Route 51 and, between Chicago and St. Louis, run near the historic U.S. Route 66 corridor.
Importance and notable facts
I-55 serves as a vital commercial artery, moving agricultural goods, manufactured products and imports from Gulf ports northward. It crosses the Mississippi River at significant urban points and passes through varied landscapes—coastal plains, river lowlands and Midwestern farmland—reflecting the economic and geographic diversity of the regions it connects.