Illinois Route 255

Illinois Route 255 (IL 255), also referred to as the Alton Bypass, is a northwesterly extension of Interstate 255 (I-255) in southwestern Illinois in the St. Louis metropolitan area. IL 255 starts at I-270 in Pontoon Beach and ends at U.S. Route 67 (US 67) in Godfrey, at a total length of approximately 23.3 miles (37.5 km). It was constructed in four segments opening from 1998 to 2012 at a total cost of $165.2 million.

Illinois Route 255
Alton Bypass
Route information
Maintained by IDOT
Length23.3 mi[1] (37.5 km)
ExistedOctober 1998[2]–present
Major junctions
South end I-255 / I-270 in Pontoon Beach
North end US 67 in Godfrey
Highway system
I-255IL 267

Route description

IL 255 is a four-lane, limited-access freeway for its entire length. It serves as an important circumferential artery for the northeastern portion of the St. Louis metropolitan area. The final segment—4.3 miles (6.9 km) from Seminary Road to US 67 in Godfrey, just north of the intersection of US 67 and Montclaire Avenue (IL 267/IL 111)—was opened on November 23, 2012. The highway passes just to the west of the St. Louis Regional Airport and Southern Illinois University Edwardsville.

Although IL 255 was designed to federal Interstate Highway standards, it was built by the Illinois Department of Transportation (IDOT) using state-provided funds.


Described as "the Road to Prosperity" by business leaders and government officials who initially proposed it in the late 1970s, IL 255 was part of a region-wide effort to create a high-speed alternative to US 67 over the Clark Bridge through the city-center of Alton, and to two congested local routes (IL 3 and IL 111) that roughly parallel the IL 255 corridor. Although it was part of the much larger Corridor 413 plan,[3] the local politicians focused mostly on the segment from I-270 to what was then IL 267 north of the Godfrey "Y" intersection. At that time, the Berm Highway, the Beltline extension, and the Madison Avenue connector were not built and both IL 3 and IL 111 were over capacity between Alton and I-270. In 1975, a six-month detour related with the closing of the Old Clark Bridge exposed the need for the Alton Bypass along with the other three routes. However, until 1985, the Alton Bypass was a low priority,[4] as other local road projects in the area were considered more important.

The roadway was constructed in four segments opening from 1998 to 2012 at a total cost of $165.2 million. The first 6.5-mile (10.5 km) segment, from I-270 to IL 143, was completed in October 1998 at the cost of $40 million (excluding land acquisition).[5] The second segment, a 7.2-mile (11.6 km) extension from IL 143 to Fosterburg Road was constructed for $78.1 million and opened on October 20, 2006, approximately one year behind schedule, owing to the 2005 collapse of the Wisconsin-based construction company that held the contracts for that portion of the roadway.[6] The $25.1 million third segment opened on August 22, 2008 and extended the road from Fosterburg Road to Seminary Road.[7] The fourth and final segment opened on November 23, 2012 and extended the road 4.3 miles (6.9 km) from Seminary Road to US 67 in Godfrey, just north of the intersection of US 67 and Montclaire Avenue (IL 267/IL 111) at a cost of $22 million.[8][9]


Now complete, the IL 255 route could be re-designated as an Interstate Highway, although there are currently no public plans to do so, as of 2018. If the corridor were to be signed as an extension of the current I-255 bypass, all exits north of I-270 would have to be renumbered. As a standalone spur route, IL 255 numbered as I-255 would violate the American Association of State Highway and Transportation Officials scheme for Interstate numbering that requires an odd-number first digit (although as part of the larger I-255 bypass the route is not technically a spur even though it extends past the segment of I-55 that it bypasses). The entire corridor from Godfrey to Mehlville, Missouri, comprising both I-255 and IL 255 could also carry secondary signage as US 67 Bypass, since it would be a true bypass of US 67, which passes through the St. Louis urban agglomeration, actually connecting with US 67 at both endpoints.

Construction of a new expressway route for US 67 between Jacksonville and Alton will follow the US 67 corridor through White Hall, Carrollton, and Jerseyville.[10] The first segment beyond IL 255—5.2 miles (8.4 km) of four-lane expressway from south of the Delhi Bypass to IL 255—was completed in 2013 at a cost of $45.6 million (equivalent to $49.5 million in 2018[11]).[12] IDOT's 2019–2024 multi-year program contains $24.4 million to construct the next 3.2 miles (5.1 km) of four-lane expressway, including the Delhi Bypass.[13] Once complete, the new US 67 expressway will end in Godfrey and travel on as IL 255, and US 67 will leave the roadway via an exit and flyover ramp—constructed during the final segment of IL 255—and proceeding south on Godfrey Road to reach Clark Bridge via the current US 67 alignment (Martin Luther King Jr. Drive) through Alton.

Exit list

The entire route is in Madison County.

Pontoon Beach0.000.00 I-255 south MemphisContinuation beyond I-270
30 I-270 Kansas City, IndianapolisSouthern terminus; exit number based on I-255 mileage; I-270 west exit 7B, east exit 7
Edwardsville1.101.772Gateway Commerce Center Drive
2.984.803 CR 69 (New Poag Road)Serves Southern Illinois University Edwardsville
Roxana5.238.425Madison Avenue South Roxana
6.5010.466 IL 143 (Edwardsville Road) Edwardsville, Wood River
Wood River8.0412.948 IL 111 (Vaughn Road/Bellwood Drive) Wood River, Bethalto
Bethalto10.3116.5910 IL 111 / IL 140 (MacArthur Drive) Alton, BethaltoSPUI interchange
13.4921.7113Fosterburg Road
16.4126.4116 CR 17 (Seminary Road)
Godfrey19Humbert Road
20 IL 111 / IL 267 (Montclaire Avenue) Godfrey
23.337.5 US 67 north JacksonvilleNorthern terminus—continues on as US Highway 67; no access to US 67 southbound from northbound IL 255
1.000 mi = 1.609 km; 1.000 km = 0.621 mi


See also

  • Illinois portal
  • U.S. Roads portal


  1. Illinois Technology Transfer Center (2006). "T2 GIS Data". Illinois Department of Transportation. Retrieved November 8, 2007.
  2. Carlson, Rich. "Routes 203 and up". Illinois Highways Page. Retrieved October 26, 2008.
  3. Dees, Dan C. (November 1, 1974). "Federal-Aid Freeway System: Supplemental Freeways" (PDF). Letter to District engineers. Illinois Department of Transportation. Retrieved February 16, 2015 via
  4. "Alton Interstate Tie-In Revived". Alton Telegraph. February 7, 1985. p. A1.
  5. Harvey, Kim (October 14, 1998). "Illinois 255: The Alton Bypass". St. Louis Highway Page. Retrieved June 2, 2006.
  6. Schmidt, Sanford J. (October 21, 2006). "New Stretch of Illinois 255 Opens". The Telegraph. Alton, IL. Retrieved October 25, 2008.
  7. "Alton Bypass" (PDF) (Press release). Illinois Department of Transportation. August 22, 2008. Archived from the original (PDF) on May 29, 2010. Retrieved October 25, 2008.
  8. Leiser, Ken (November 23, 2012). "Final Stretch of Highway 255 Now Open". St. Louis Post-Dispatch. Retrieved November 24, 2012.
  9. 618-659-2075, TERRY HILLIG • >. "Remaining sections of Illinois 255 freeway expected to open in October". Retrieved November 26, 2018.
  10. Illinois Department of Transportation (n.d.). "US 67 Corridor". Illinois Department of Transportation. Retrieved December 2, 2018.
  11. Thomas, Ryland; Williamson, Samuel H. (2019). "What Was the U.S. GDP Then?". MeasuringWorth. Retrieved April 6, 2019. United States Gross Domestic Product deflator figures follow the Measuring Worth series.
  12. Grubaugh, Dennis (September 2018). "Rail Developers Join Push to Complete US 67". Illinois Business Journal. Retrieved December 2, 2018.
  13. Illinois Department of Transportation (2018). 2019-2024 IDOT Multi-Year Plan (PDF). Springfield: Illinois Department of Transportation. Retrieved December 2, 2018.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.