Interstate 255 (I-255) is a

bypass route A bypass is a road or highway that avoids or "bypasses" a built-up area, town, or village, to let through traffic flow without interference from local traffic, to reduce congestion in the built-up area, to improve road safety and as replacement ...

of I-55 in

Greater St. Louis Greater St. Louis is the 23rd-largest metropolitan statistical area (MSA) in the United States, the largest in Missouri, and the second-largest in Illinois. Its core city—St. Louis, Missouri—sits in the geographic center of the metro area, ...

. Along with I-270, it forms a loop around the central portion of the bi-state metro area; a majority of I-255 is located on the Illinois half. It shares its southern terminus with I-270 at the junction with I-55; I-270 and I-255 go to the west and east, respectively.

U.S. Route 50 U.S. Route 50 or U.S. Highway 50 (US 50) is a major east–west route of the U.S. Highway system, stretching from Interstate 80 (I-80) in West Sacramento, California, to Maryland Route 528 (MD 528) in Ocean City, Maryland, on the Atlantic ...

(US 50) joins I-255 at Lemay Ferry Road. It crosses the

Mississippi River The Mississippi River is the main stem, primary river of the largest drainage basin in the United States. It is the second-longest river in the United States, behind only the Missouri River, Missouri. From its traditional source of Lake Ita ...

on the Jefferson Barracks Bridge, enters Illinois, and then turns northeast. There is a junction with I-64, where US 50 breaks off and goes east, and then further north there is a junction with I-55 again, I-70, and US 40, all of which are all cosigned together. The next junction is another one with I-270, which is the northern terminus of I-255. After that, the limited-access freeway continues on as Illinois Route 255 (IL 255). I-255 is in length.

Route description

I-255's counterclockwise terminus is at an interchange with I-55 and I-270 in Mehlville, Missouri. The beltway is designated as I-270 (with

Kansas City The Kansas City metropolitan area is a bi-state metropolitan area anchored by Kansas City, Missouri. Its 14 counties straddle the border between the U.S. states of Missouri (9 counties) and Kansas (5 counties). With and a population of more t ...

as the control city) west of this interchange and as I-255 east (with

Chicago Chicago is the List of municipalities in Illinois, most populous city in the U.S. state of Illinois and in the Midwestern United States. With a population of 2,746,388, as of the 2020 United States census, 2020 census, it is the List of Unite ...

as the control city) east of this interchange. The section of I-255 east from this interchange to the Jefferson Barracks Bridge was first built in the 1960s to carry US 50 traffic across the Mississippi River. The roadway was upgraded between 2002 and 2004. Repairs included both new pavement and the replacement of the Telegraph Road bridge. Once it crosses the Mississippi River and enters Illinois, I-255 is signed as a north–south highway. It is considerably newer than the Missouri section; it was constructed in the 1980s. At the IL 3 interchange, I-255 turns sharply to the north. It briefly overlaps with IL 3 in Dupo. After Dupo, I-255 turns northeast, skirting

Cahokia Cahokia Mounds ( 11 MS 2) is the site of a Native American city (which existed 1050–1350 CE) directly across the Mississippi River from present-day St. Louis. The state archaeology park lies in south-western Illinois between East St. L ...

and East St. Louis. An interchange at Mousette Lane in Sauget was constructed in the 1990s and provides motorist access to GCS Ballpark (home to the Gateway Grizzlies baseball team) and the St. Louis Downtown Airport. Given its proximity to the airport, this section of I-255 features shorter light poles to better accommodate takeoffs and landings. North of Sauget, I-255 traverses a portion of the Frank Holten State Recreation Area before an interchange with I-64 west of Caseyville. This section of freeway opened in 1986. Traffic can enter and exit I-255 at an interchange with Collinsville Road (formerly US 40) just east of the Fairmont Park Racetrack. I-255 meets I-55/I-70 at an interchange in Collinsville, its original intended terminus. North of this interchange, the control city for I-255 changes from "Chicago" to "To I-270". In the 1980s, I-255 was extended approximately north to meet I-270 in Pontoon Beach, its current terminus. While the I-255 designation ends at the I-270 interchange, the freeway continues north and west (parallelling the bend in the Mississippi River) for approximately as IL 255. The decision to not extend the I-255 designation to the new freeway reflects the fact that state and not federal funds were used to pay for construction.

History

I-255 route was proposed from I-55/I-244 near

Green Park The Green Park, one of the Royal Parks of London, is in the City of Westminster, Central London. Green Park is to the north of the gardens and semi-circular forecourt of Buckingham Palace, across Constitution Hill road. The park is in the m ...

to I-55/70 west of

Cahokia Mounds Cahokia Mounds ( 11 MS 2) is the site of a Native American city (which existed 1050–1350 CE) directly across the Mississippi River from present-day St. Louis. The state archaeology park lies in south-western Illinois between East St. L ...

near the intersection with IL 111 when plans surfaced in the 1950s Yellow Book. It was originally designed to be a four lane highway but was changed to six lanes. Since that routing was to go through the American Bottoms, archaeological investigations had to be conducted prior to any construction, which would later become known as the FAI 270 Series. When Cahokia Mounds was designated in the federal register, an alternative alignment for I-255 from I-64 to I-55/70 was selected. This delayed construction of I-255 until the late 1970s, making it the last Interstate Highway in metropolitan St. Louis to be built. Both the western (I-270) and eastern (I-255) portions of the Interstate loop around St. Louis were originally designated as I-270. However, the route that Illinois selected ("Corridor 413") included an interchange in Pontoon Beach between the new beltway (running north and south parallel to the Mississippi River) and the existing beltway (running east and west to a terminus at I-55/I-70). As such, two intersecting Interstate Highways would have carried the same route number.IDOT FAI-270/FAP 413 Draft EIS Volume 1, 1983 As such, the

Illinois Department of Transportation The Illinois Department of Transportation (IDOT) is a state agency in charge of state-maintained public roadways of the U.S. state of Illinois. In addition, IDOT provides funding for rail, public transit and airport projects and administers f ...

(IDOT) concluded a different route number would be necessary for the eastern leg of the beltway. While I-870 was initially considered,I-270/870 proposed routes
/ref> informal use of I-255 in contemporary local media coverage led to its widespread adoption. By 1980, IDOT announced that the eastern portion of the St. Louis beltway was to be designated as I-255.

Exit list

References

External links

{{Authority control 55-2 2 55-2 55-2 Roads in Greater St. Louis Transportation in Madison County, Illinois Transportation in Monroe County, Illinois Transportation in St. Clair County, Illinois Transportation in St. Louis County, Missouri Beltways in the United States