Illinois Route 23

Illinois Route 23 (IL 23) is a north–south state highway in northern Illinois. It runs from Illinois Route 116 in Pontiac north to U.S. Route 14 south of Harvard. This is a distance of 122.77 miles (197.58 km).[2]

Illinois Route 23 marker

Illinois Route 23
IL 23 highlighted in red
Route information
Maintained by IDOT
Length122.77 mi[2] (197.58 km)
ExistedNovember 5, 1918[1]–present
Major junctions
South end IL 116 in Pontiac
  I-55 in Pontiac
US 6 / IL 71 in Ottawa
I-80 in Ottawa
US 52 in Serena
US 34 in Leland
US 30 in Waterman

I-90 near Marengo
US 20 in Marengo
North end US 14 in Harvard
CountiesLivingston, LaSalle, DeKalb, McHenry
Highway system
IL 22I-24

Illinois 23 was established in 1918 as one of the original 46 SBI routes. The routing of Illinois 23 has not changed since its establishment.

Route descriptionEdit

Illinois 23 is a major arterial route in rural central and north-central Illinois. It is a parallel to the Interstate 39/U.S. Route 51 combination approximately 20 miles (32 km) to the west.

The road starts near downtown Pontiac and runs as the main highway north, intersecting with Interstate 55 and former U.S. Route 66. From this point, Illinois 23 continues as a 2-lane highway, turning west and running through Cornell. After that, it turns back north to travel through the middle of Streator, where the route splits to follow two different one-way streets (Park Street and Bloomington Street). Route 23 continues through Grand Ridge to Ottawa, where the road follows 1st Ave and State street, to form a concurrent with Illinois Route 71—Illinois 71 across the Illinois River. The highway once again splits into two one-way streets (Columbus and LaSalle Streets) through downtown Ottawa, until a block south of its junction with U.S. Route 6, where Illinois 71 departs toward the east.

North of Ottawa, Illinois 23 has a full diamond interchange with Interstate 80. Illinois 23 has two additional concurrencies with U.S. Route 34 and U.S. Route 52, though no notable cities are present between Ottawa and DeKalb. Illinois 23 runs under Interstate 88 with no interchange, though access is available via Fairview Drive to two parallel roads with interchanges (Peace Road and Annie Glidden Road). Between DeKalb and Sycamore, Illinois 23 has four lanes. In Sycamore, Illinois 23 briefly overlaps Illinois Route 64. After one final concurrency at Illinois Route 72 near Genoa, Illinois 23 has an interchange with Interstate 90. It runs through Marengo and terminates south of Harvard at U.S. Route 14.

Major intersectionsEdit

LivingstonPontiac0.00.0   IL 116 (Howard Street) / Historic US 66 southSouth end of Historic US 66 overlap
0.40.64  Historic US 66 northNorth end of Historic US 66 overlap
2.64.2  I-55 – Joliet, BloomingtonI-55 exit 201
7.411.9  IL 170 north
21.935.2  IL 17
La SalleStreator26.041.8  IL 18 (Bridge Street, Main Street)
Ottawa41.366.5  IL 71 west (Hitt Street)South end of IL 71 overlap
Illinois River41.466.6Ottawa Bridge
Ottawa42.468.2   US 6 / IL 71 east (Norris Drive)North end of IL 71 overlap
43.970.7  I-80 – Joliet, Moline, Rock IslandI-80 exit 90
50.481.1  US 52 west (North 37th Road)South end of US 52 overlap
52.484.3  US 52 east (North 38th Road)North end of US 52 overlap
59.595.8  US 34 west (Walter Payton Memorial Highway)South end of US 34 overlap
63.6102.4  US 34 east (Walter Payton Memorial Highway)North end of US 34 overlap
DeKalbWaterman74.3119.6  US 30 (Lincoln Street)
DeKalb85.4137.4  IL 38 (Lincoln Highway)
Sycamore90.8146.1  IL 64 west (State Street)South end of IL 64 overlap
91.4147.1  IL 64 east (State Street)North end of IL 64 overlap
Genoa98.9159.2  IL 72 west (Main Street)South end of IL 72 overlap
100.9162.4  IL 72 eastNorth end of IL 72 overlap
  I-90 (Jane Addams Memorial Tollway) – Chicago, Rockford
I-Pass only; I-90 exit 36
Marengo112.2180.6  US 20 (General Grant Highway)
112.7181.4  IL 176 (Telegraph Street)
Harvard126.17203.05  US 14 (Division Street)
1.000 mi = 1.609 km; 1.000 km = 0.621 mi


  • In downtown DeKalb, Route 23 (the main north–south street) intersects as 4th Street with Illinois Route 38 (the main east–west street) at a railroad crossing, as two Union Pacific tracks pass through the crossing. Trains routinely bring traffic in DeKalb to a halt.


  1. ^ Carlson, Rick. Illinois Highways Page: Interstates in Illinois. Last known update March 15, 2006. Retrieved March 21, 2006.
  2. ^ a b Illinois Technology Transfer Center (2007). "T2 GIS Data". Retrieved 2007-11-08.
  3. ^ Google Maps, [1]

External linksEdit

Route map:

KML is from Wikidata