Interstate 180 (I-180) is a north–south spur highway in Illinois that runs from Princeton to the small town of Hennepin at its southern terminus. It is 13.19 miles (21.23 km) long.

Route description

I-180 begins as a continuation of Illinois Route 71 (IL 71) at a diamond interchange with IL 26 northeast of Hennepin. The interchange is located adjacent to a former steel mill that was most recently operated by ArcelorMittal but closed in 2009 and demolished in 2017. The freeway travels northwest, carrying I-180 and IL 26 in a concurrency, and crosses the Illinois River on the north side of Hennepin to enter Bureau County.

On the west side of the river, IL 26 separates from I-180 and the freeway crosses over IL 29 before splitting at a Y interchange. I-180 turns north, intersecting an expressway that connects to IL 29, and travels northeast across Big Bureau Creek to intersect IL 26. The freeway intersects US Route 6 (US 6) east of Princeton and continues due north to its terminus, a trumpet interchange with I-80. I-180 has four lanes for most of its length, though an additional 1.5-mile (2.4 km) southbound lane exists prior to the IL 29 exit.

History

Construction of I-180 was completed in 1969. The freeway was built primarily to connect I-80 to a new Jones and Laughlin Steel Company steel plant built in 1965 in Hennepin. Federal auditors criticized its construction and called it a political favor that was put ahead of requests from Tucson, Arizona, and Tacoma, Washington. The steel plant closed in 2009 and has since been demolished.

I-180 is one of the least traveled Interstates in the nation, serving 1,950–3,600 vehicles per day as of 2013.

In the 2010s, work started to reconstruct portions of the bridge carrying I-180 over the Illinois River. A three-year project to rebuild the deck began in 2020.

Exit list

County	Location	mi	km	Exit	Destinations	Notes
Putnam	Hennepin	0.00	0.00	14	IL 26 – Hennepin, Lacon IL 71 east	Southern end of IL 26 concurrency; roadway continues as IL 71
Illinois River		1.0	1.6	Gudmund "Sonny" Jessen Bridge
Bureau	Bureau Junction	2.5	4.0	12	IL 26 north – Bureau Junction	Northern end of IL 26 concurrency; northbound exit and southbound entrance
		3.5	5.6	—	To IL 29 south – Peoria	Access via unnamed connector expressway
		8.0	12.9	7	IL 26 – Princeton
	Princeton	12.0	19.3	3	US 6 (Grand Army of the Republic Highway) – Princeton, Spring Valley
		13.2	21.2	—	I-80 – Davenport, Joliet	Northern terminus; I-80 exit 61
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Concurrency terminus