Interstate 172

Route information

Maintained by IDOT

Length:

19.69 mi (31.69 km)

Existed:

1995 – present

Major junctions

South end:

North end:

Highway system

Illinois State Highway System

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Interstate 172 (I-172) is a spur route from Interstate 72. The highway runs north from its start outside of Hannibal, Missouri to just two miles (3 km) west of Fowler, Illinois. At U.S. Highway 24, Interstate 172 becomes Illinois Route 336, which runs north and east to Macomb, Illinois via Carthage, Illinois. The entire portion of I-172 and I-72 from I-172 east to Springfield is also known by its former name, the Central Illinois Expressway. I-172 is 19.69 miles (31.69 km) long.

Interstate 172 begins at an trumpet interchange with its parent route, I-72, about five miles east of Hannibal, MO, before immediately crossing into Adams County. I-172 enters the Quincy area at exit 10 (State Route 96), passing to the far east of the city. I-172 ends just northeast of Quincy, ending at US 24, continuing north as State Route 110/336.

Interstate 172 originally was what Interstate 72 is now from Springfield, Illinois to the current interchange with I-172. This was approved by the American Association of State Highway and Transportation Officials (AASHTO) on June 9, 1991.