Interstate 55 parallels the Mississippi River for much of its length. The route originates at Interstate 10 outside the city of La Place, located west of New Orleans in the Delta region. The freeway runs northward along an isthmus between Lakes Maurepas and Pontchartrain between LaPlace and Ponchatola. This section of Interstate 55 is elevated. Meeting I-12 at Hammond, I-55 transitions into a forested freeway to McComb and Brookhaven in southern Mississippi.
Reaching the capital city of Jackson, Interstate 55 briefly joins Interstate 20 to turn east across the Pearl River. The freeway resumes a northward heading east of Downtown to Ridgeland, Madison and the north Jackson suburbs. Again a rural freeway, I-55 continues to Grenada, Senatobia, Hernando and the southern periphery of the Memphis metropolitan area.
As of May 6, 2008, Interstate 55 combines with Interstate 69 from north of Hernando to the city of Memphis and the exchange with Interstate 240. I-69 follows I-240 north to Downtown Memphis while I-55 swings westward to span the Mississippi River via the Memphis & Arkansas Bridge. Along this stretch is a cloverleaf interchange with Crump Boulevard that includes a turn off to stay on (TOTSO) mainline movement for I-55. Construction originally anticipated through 2019, and temporarily on hold, addresses this substandard connection.
Interstate 40 combines with I-55 for two miles at West Memphis. The two trucking corridors partition with I-55 turning north to Marion and Blytheville and the Missouri state line. Remaining rural, Interstate 55 progresses northward to Hayti (I-155), New Madrid, and Sikeston (I-57). Some through traffic bound for Chicago diverts via Interstate 57 while I-55 stays west of the Mississippi to St. Louis.
Beyond Cape Girardeau, Jackson and Festus, all served by Interstate 55 business loops, travelers along I-55 enter the St. Louis suburbs to Mehlville and the exchange with I-270 and I-255. These routes double as bypasses and commuter routes while I-55 stays north into Downtown St. Louis.
Crossing the Mississippi River for a second time, I-55 joins Interstate 64 & U.S. 40 from near the Gateway Arch into East St. Louis. There I-70 ties in from the 2014-opened Stan Musial Veterans Memorial Bridge to replace I-64 as the northbound counterpart of I-55 to Troy.
The remainder of Interstate 55 through Illinois replaced U.S. 66. Most stretches of Old U.S. 66 are marked as an historical route, and stretches through both Springfield and Lincoln double as Business Loop I-55. The freeway overlaps with Interstate 72 through the capital city of Springfield before angling northeast to Lincoln, Bloomington and Normal.
Interstate 74 combines with I-55 to the west of Bloomington while I-39 ends from the north at Normal. Interstate 55 continues northeast from there to Joliet (I-80) and the Stephenson Expressway leading into Chicago. The northern terminus of I-55 is in Downtown Chicago at Lake Shore Drive (U.S. 41) near the sprawling McCormick Place, the city’s convention center.
Parallel U.S. Routes
Interstate 55 parallels U.S. 51 from New Orleans north to Memphis, then follows U.S. 61 from Memphis north to St. Louis. Between Memphis and St. Louis, U.S. 51 remains east of the Mississippi River, while Interstate 55 stays west of the river. Once at St. Louis, I-55 replaced U.S. 66 all the way to Chicago. U.S. 51 and Interstate 55 meet again at Bloomington-Normal, and U.S. 51 north of that city has been largely subsumed by Interstate 39.
The first section of Interstate 55 approved for construction in Mississippi was a 27-mile segment through Hernando, Coldwater and Senatobia. The contract was advertised in late 1956, and groundbreaking for construction followed in July 1957 in Coldwater.2
Interstate 55 was completed between Exit 49 (U.S. 61), north of New Madrid, Missouri, to U.S. 60 at Sikeston, Missouri on September 1, 1960. An eight mile stretch of freeway opened that day, tieing in with a preexisting seven mile stretch.3 Further north in St. Louis, Interstate 55 was completed between the Jefferson County line and downtown by 1967.4
Interstate 55 in Chicago, Illinois, follows the Stevenson Expressway. This freeway, which was originally known as the Southwest Expressway, extended from the Cook-DuPage County Line northeast to Interstates 90 & 94 (Dan Ryan Expressway). The expressway opened to traffic on September 1, 1964. Exactly one year later, the Southwest Expressway was renamed the Adlai E. Stevenson Expressway on September 1, 1965, in memory of the former Illinois state governor. The last section of I-55 completed in Chicago was the short extension from I-90/94 (Dan Ryan Expressway) east to U.S. 41 (Lake Shore Drive) in 1966.5,6
North End – Chicago, IL
South End – La Place, LA
Branch Routes – 5
Total Mileage – 964.25
Louisiana – 65.81
- Cities – Hammond
- Junctions –
Mississippi – 290.41
- Cities – McComb, Brookhaven, Jackson, Canton, Winona, Southaven
- Junctions –
Tennessee – 12.28
Cities – Memphis
- Junctions –
Arkansas – 72.22*
Cities – West Memphis, Blytheville
- Junctions –
Missouri – 210.45#
Cities – Sikeston, Cape Girardeau, Perryville, St. Louis
Illinois – 313.08+
Cities – East Saint Louis, Edwardsville, Litchfield, Springfield, Lincoln, Bloomington, Pontiac, Joliet, Chicago
Source: December 31, 2017 Interstate Route Log and Finders List
* – 2.22 miles on I-40, # – 1.00 mile on I-44, 0.40 miles on I-64,+ – 2.70 miles on I-64. 16.00 miles on I-70
I-55 Annual Average Daily Traffic (AADT)
|Location||Vehicles per day|
Source: Louisiana 2001 Traffic Volume Monitoring (LADOTD)
Traffic Flow Maps – Tennessee Roads and Streets 2002 (TDOT)
The portion of I-55 between MS 16 north of Canton (Exit 124) and Vaiden (Exit 174) was the last section of Interstate 55 opened in Mississippi. It was completed in 1973.7
Through southeastern Missouri, Interstate 55 was completed initially at the Arkansas state line and from Sikeston north to Jackson.
North End (Lake Shore Drive) – Chicago, Illinois
South End – La Place, Louisiana
- Tennessee Interstate System at 50: Facts and Trivia
- Celebrating the 50th Anniversary of the Eisenhower Interstate Highway System: Previous Interstate Facts of the Day by the Federal Highway Administration (FHWA).
- “New Highway Stretch Open.” The Southeast Missourian, September 2, 1960.
- Vintage St. Louis, online posting. Facebook.com. July 14, 2013.
- Chicago Timeline: 1964 Southwest Expressway Opened; September 1, 1965–Renamed Adlai E. Stevenson Expressway, Chicago Public Library, updated August 1997
- Encyclopedia of Chicago: Expressways by Dennis McClendon of the Chicago Historical Society
- Interstate Highway 55, Adam Froehlig.
Page updated June 10, 2018.