Illinois Route 174 was a state highway in Illinois

Illinois

Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...

 from 1924 to 1983. The route connected Illinois Route 40

Illinois Route 40

Illinois Route 40 is a north–south route in central portion of the U.S. state of Illinois. It runs from Interstate 74 in East Peoria north to Illinois Route 78 at Mt. Carroll, just south of U.S. Route 52 and Illinois Route 64. This is a distance of ....

 (then Illinois Route 88) and Illinois Route 91

Illinois Route 91

Illinois Route 91 is a rural state road in central Illinois. It runs from the northwest edge of Peoria at U.S. Highway 150 to U.S. Highway 34 south of Kewanee. Illinois 91 is long.- Route description :...

 through the community of Alta

Alta, Illinois

Alta is an unincorporated community on the northwest border of Peoria in Peoria County, Illinois, United States. Alta is north-northwest of downtown Peoria. The decommissioned Illinois State Route 174 runs through Alta, and the Rock Island Trail begins in Alta....

. Its only junction with a numbered highway between these two routes was with Illinois Route 6

Illinois Route 6

Illinois Route 6 is a 4-lane freeway in central Illinois. It begins as a northern extension of Interstate 474 at Interstate 74 west of Peoria, and ends at Illinois Route 29 in Mossville, south of Chillicothe...

; the road is still an exit from that route.

Route 174 was established in 1924 as part of the later series of State Bond Issue (SBI) Routes. It was decommissioned in 1983 and has been unnumbered since.