IL 31 highlighted in red
|Maintained by IDOT|
|Length||58.41 mi (94.00 km)|
|South end||US 34 in Oswego|
|North end||US 12 / CR A16 in Richmond|
|Counties||Kendall, Kane, McHenry|
Illinois Route 31 (IL 31) is a 58.41-mile-long (94.00 km) north–south state road in northeastern Illinois, United States. It travels from U.S. Route 34 (US 34) in Oswego north to US 12, near the Wisconsin state line, just south of Richmond.
IL 31 is called Richmond Road north of IL 120 and Front Street south of IL 120 in McHenry, Main Street in Algonquin, Western Avenue in Carpentersville, Eighth Street in West Dundee, State Street in Elgin, La Fox Street in South Elgin, Second Street in St. Charles, First Street in Geneva, Batavia Avenue in Batavia, Lincolnway Street in North Aurora, Lake Street (Southbound) and River Street (Northbound) in Aurora, and Lake Street in Montgomery. It is also, along with IL 25, signed as part of the Fox River Valley area. IL 31 between Aurora and Geneva was considered part of the Lincoln Highway transcontinental route.
SBI Route 31 traveled from Quincy to Canton along various routes. This was dropped in 1935. In 1937, it was reapplied along other routes on its modern routing. There have been no changes to the routing since.
U.S. Route 430
U.S. Route 430 (US 430) was commissioned from 1926 to 1934 in the U.S. state of Illinois, and traveled from Aurora to Crystal Lake. It traveled concurrent with US 30 from Aurora to Geneva at present-day IL 38. US 430 was dropped in 1934 and replaced in its entirety with IL 31.
The intersection of IL 31 and IL 120 is now the most congested intersection in McHenry County.
A bypass of McHenry continues to appear in documents planning for a Metra station at Prairie Grove, that include an interchange with the existing IL 31 alignment and the proposed west McHenry bypass alignment to the north of Gracy Road.
The west McHenry bypass was originally planned to travel over undeveloped farm lands from north of IL 31 and Gracy Road to IL 120 and Ringwood Road. The corridor was planned to be protected from development in the mid-1990s, but because of a lack of funding, the corridor was never protected from development and has since been developed.
The Western Algonquin Bypass is not the only limited-access bypass on the table as of 2015. A southern Algonquin bypass is being constructed as the Longmeadow Parkway, that will have a grade separation with Route 31.
|Kendall||Oswego||0.0||0.0||US 34 (Washington Street, Walter Payton Memorial Highway)||Southern terminus of IL 31|
|Kane||Montgomery||2.8||4.5||US 30 (Base Line Road) – Joliet, Sugar Grove||Interchange|
|Aurora||5.6||9.0||Lincoln Highway east (Benton Street)||Southern end of Lincoln Highway concurrency|
I-88 / IL 56 west / IL 110 (CKC) (Ronald Reagan Memorial Tollway) – DeKalb, Chicago
|Southern end of IL 56 concurrency; I-88 exit 117|
|9.4||15.1||IL 56 east (West State Street)||Northern end of IL 56 concurrency|
|10.3||16.6||CR 71 west (Mooseheart Road)|
|Batavia||13.7||22.0||CR 8 (Fabyan Parkway)|
|Geneva||15.4||24.8||IL 38 (State Street) / Lincoln Highway west|
|St. Charles||17.4||28.0||IL 64 (Main Street)|
|Elgin||26.4||42.5||US 20 (Elgin Bypass, Dr. Martin Luther King Jr. Memorial Highway, Grant Highway) – Rockford, Chicago||Interchange|
I-90 (Jane Addams Memorial Tollway) – Chicago, Wisconsin
|I-90 exit 54; cloverleaf interchange|
|West Dundee||31.9||51.3||IL 72 (Main Street)|
|McHenry||Algonquin||37.0||59.5||IL 62 east / CR A48 west (Algonquin Road)||Western terminus of IL 62; Interchange|
|Crystal Lake||41.2||66.3||US 14 (Northwest Highway, Ronald Reagan Highway)||Interchange|
|42.8||68.9||IL 176 (Terra Cotta Avenue)|
|McHenry||49.5||79.7||IL 120 west (Elm Street)||Western end of IL 120 concurrency|
|49.9||80.3||IL 120 east (Elm Street)||Eastern end of IL 120 concurrency|
|Richmond||57.9||93.2||US 12 / CR A16 west (Tryon Grove Road)|
|1.000 mi = 1.609 km; 1.000 km = 0.621 mi|
Algonquin business route
|Length||1.12 mi (1.80 km)|
|Existed||August 31, 2014–present|
Illinois Route 31 Business, also known as Main Street-Algonquin, is a business route that runs about 1.12 miles (1.80 km). Illinois Route 31 Business runs through Algonquin and McHenry County in Illinois. This business route has been announced since October 2013 for the Western Algonquin Bypass groundbreaking. It had already been designated when the Western Algonquin Bypass was completed.
- Carlson, Rich (March 15, 2006). "Routes 21 thru 40". Illinois State Highways Page. Retrieved March 22, 2006.[self-published source]
- Illinois Technology Transfer Center (2007). "T2 GIS Data". Illinois Department of Transportation. Retrieved November 8, 2007.
- "Algonquin Western Bypass opens to traffic". Northwest Herald. Retrieved December 8, 2016.
- "Illinois Route 31 Study". Retrieved February 13, 2017.
- "Town Center & Transit-Oriented Development Plan" (PDF). Village of Prairie Grove, Illinois. Retrieved December 29, 2015.
- "County Maps Out Bypass". Chicago Tribune. August 8, 1995. Retrieved December 29, 2015.
- Google (December 29, 2015). "Overview Map of Illinois Route 31" (Map). Google Maps. Google. Retrieved December 29, 2015.
- "Construction Project: Longmeadow Parkway Bridge Corridor". Kane County Department of Transportation. Retrieved December 29, 2015.
- Google (January 2, 2013). "Illinois Route 31" (Map). Google Maps. Google. Retrieved January 2, 2013.
|Wikimedia Commons has media related to Illinois Route 31.|