 Illinois Route 23 | ||||
|---|---|---|---|---|
 IL 23 highlighted in red | ||||
| Route information | ||||
| Maintained byIDOT | ||||
| Length | 122.77 mi[1] (197.58 km) | |||
| Existed | November 5, 1918[2]–present | |||
| Major junctions | ||||
| South end |  IL 116 inPontiac | |||
| Major intersections |  I-55 inPontiac  US 6 /IL 71 inOttawa I-80 inOttawa US 52 inSerena US 34 inLeland US 30 inWaterman  I-90 Toll nearMarengo US 20 inMarengo | |||
| North end |  US 14 inHarvard | |||
| Location | ||||
| Country | United States | |||
| State | Illinois | |||
| Counties | Livingston,LaSalle,DeKalb,McHenry | |||
| Highway system | ||||
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Illinois Route 23 (IL 23) is a north–south state highway in northernIllinois. It runs fromIllinois Route 116 inPontiac north toU.S. Route 14 south ofHarvard. This is a distance of 122.77 miles (197.58 km).[1]
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.
Illinois 23 is a major arterial route in rural central and north-central Illinois. It is a parallel to theInterstate 39/U.S. Route 51 combination approximately 20 miles (32 km) west.
The road starts near downtownPontiac and runs as the main highway north, intersecting withInterstate 55 and formerU.S. Route 66. Illinois 23 continues as a 2-lane highway from this point, turning west and running throughCornell. After that, it turns back north to travel through the middle ofStreator, where the route splits to follow two different one-way streets (Park Street and Bloomington Street). Route 23 continues throughGrand Ridge toOttawa, where the road follows 1st Avenue and State Street, to form aconcurrency withIllinois Route 71 across theIllinois 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 withU.S. Route 6, where Illinois 71 departs toward the east.
North of Ottawa, Illinois 23 has a full diamond interchange withInterstate 80. Illinois 23 has two additional concurrencies withU.S. Route 34 andU.S. Route 52, though no notable cities are present between Ottawa andDeKalb. Illinois 23 runs underInterstate 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 andSycamore, Illinois 23 has four lanes. In Sycamore, Illinois 23 briefly overlapsIllinois Route 64. After one final concurrency atIllinois Route 72 nearGenoa, Illinois 23 has an interchange withInterstate 90. It intersectsU.S. Route 20 and the western terminus ofIllinois Route 176 inMarengo, and terminates south of Harvard atU.S. Route 14.
| County | Location | mi[3] | km | Destinations | Notes |
|---|---|---|---|---|---|
| Livingston | Pontiac | 0.00 | 0.00 |   IL 116 (Howard Street) /Historic US 66 west | South end of Historic US 66 overlap |
| 0.4 | 0.64 |  Historic US 66 east | North end of Historic US 66 overlap | ||
| | 2.6 | 4.2 | I-55 (Barack Obama Presidential Expressway) –Joliet,Bloomington | I-55 exit 201 | |
| | 7.4 | 11.9 |   IL 170 north (North 1500 East Road) | ||
| | 21.9 | 35.2 |  IL 17 (East 3000 North Road) | ||
| LaSalle | Streator | 26.0 | 41.8 |  IL 18 (Bridge Street, Main Street) | |
| Ottawa | 41.3 | 66.5 |  IL 71 west (Hitt Street) | South end of IL 71 overlap | |
| 41.4 | 66.6 | Ottawa Bridge over theIllinois River | |||
| 42.4 | 68.2 |  US 6 /IL 71 east (Norris Drive) | North end of IL 71 overlap | ||
| 43.9 | 70.7 | I-80 –Joliet,Moline,Rock Island | I-80 exit 90 | ||
| Harding | 50.4 | 81.1 | US 52 west (North 37th Road) | South end of US 52 overlap | |
| Serena | 52.4 | 84.3 | US 52 east (North 38th Road) | North end of US 52 overlap | |
| Leland | 59.5 | 95.8 | US 34 west (Walter Payton Memorial Highway) | South end of US 34 overlap | |
| Somonauk | 63.6 | 102.4 | US 34 east (Walter Payton Memorial Highway) | North end of US 34 overlap | |
| DeKalb | Waterman | 74.3 | 119.6 | US 30 (Lincoln Street) | |
| DeKalb | 85.4 | 137.4 |  IL 38 (Lincoln Highway) | ||
| Sycamore | 90.8 | 146.1 |  IL 64 west (State Street) | South end of IL 64 overlap | |
| 91.4 | 147.1 | IL 64 east (State Street) | North end of IL 64 overlap | ||
| Genoa | 98.9 | 159.2 |  IL 72 west (Main Street) | South end of IL 72 overlap | |
| New Lebanon | 100.9 | 162.4 | IL 72 east | North end of IL 72 overlap | |
| McHenry | Riley | 107.2 | 172.5 | I-90 Toll (Jane Addams Memorial Tollway) –Chicago,Rockford | I-Pass only; I-90 exit 36 |
| Marengo | 112.2 | 180.6 | US 20 (General Grant Highway) | ||
| 112.7 | 181.4 |  IL 176 (Telegraph Street) | |||
| | 118.9 | 191.4 |   CR A29 east (Dunham Road) | ||
| Harvard | 126.17 | 203.05 | US 14 (Division Street) | ||
1.000 mi = 1.609 km; 1.000 km = 0.621 mi
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