Illinois Route 251 is a north–south state highway that runs on the former alignment of

U.S. Route 51 U.S. Route 51 or U.S. Highway 51 (US 51) is a major south-north United States highway that extends from the western suburbs of New Orleans, Louisiana, to within of the Wisconsin–Michigan state line. As most of the United States Numbered Highw ...

before

Interstate 39 Interstate 39 (I-39) is a highway in the Midwestern United States. I-39 runs from Normal, Illinois, at I-55 to State Trunk Highway 29 (WIS 29) in the town of Rib Mountain, Wisconsin, which is approximately south of Wausau. I- ...

was built in north central

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...

. It runs from U.S. 51 at the border with

Wisconsin Wisconsin () is a state in the upper Midwestern United States. Wisconsin is the 25th-largest state by total area and the 20th-most populous. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake M ...

to I-39 and U.S. 51 south of

Kappa Kappa (uppercase Κ, lowercase κ or cursive ; el, κάππα, ''káppa'') is the 10th letter of the Greek alphabet, representing the voiceless velar plosive sound in Ancient and Modern Greek. In the system of Greek numerals, has a value o ...

. Illinois 251 is long.

Route description

Illinois 251 runs parallel to Interstate 39 and U.S. 51 for most of the length of I-39 in Illinois. Like

Illinois Route 351 Illinois Route 351 is a north–south state route that leads from Illinois Route 71 and Illinois Route 251 by Oglesby through downtown LaSalle to Interstate 80. It is long. Route description Illinois 351 is the former Business U.S. Route 5 ...

, it can be considered a spur, loop or alternate of its parent route, U.S. 51. Illinois 251 terminates about north of the southern terminus of I-39. The road parallels the east bank of the Rock River through Rockford, where the highway goes north on Eleventh Street, west on Harrison, north on Kishwaukee, west on Walnut then split between northbound Third and southbound Second through downtown Rockford. After downtown, both directions take the southbound lanes' Second Street name as a divided urban expressway (also badged as Martin Luther King Jr. Memorial Drive) for a couple of miles north of downtown Rockford. It stays Second Street through Loves Park, Machesney Park and Roscoe until its north endpoint at

US 51 U.S. Route 51 or U.S. Highway 51 (US 51) is a major south-north United States highway that extends from the western suburbs of New Orleans, Louisiana, to within of the Wisconsin–Michigan state line. As most of the United States Numbered Highw ...

and

Illinois 75 Illinois Route 75 (IL 75) is an east–west state highway in north-central Illinois. It runs from downtown Freeport at Illinois Route 26 to WIS 67 at the Wisconsin state line southeast of Beloit, Wisconsin. This is a distance of . Route d ...

in South Beloit

History

Illinois 251 was established in 1982 when first segment of I-39 opened between Rockford and Bloomington. In 1992, the final segment of I-39 opened north of Bloomington. The remaining stretch of former U.S. 51 became Illinois 251.AARoads
Interstate 39 @ Interstate-Guide.com
The initial designation of I-39 was U.S. Route 51 until 1992.

Major intersections

References

External links

Illinois Highway Ends: Illinois Route 251
{{Attached KML, display=title,inline 251 251 Transportation in McLean County, Illinois Transportation in Woodford County, Illinois Transportation in Marshall County, Illinois Transportation in LaSalle County, Illinois Transportation in Lee County, Illinois Transportation in Ogle County, Illinois Transportation in Winnebago County, Illinois Transportation in Rockford, Illinois