Iroquois County, IL

565 public highway bridges

Iroquois County Bridge Snapshot

Iroquois County, Illinois contains 565 public highway bridges in the FHWA National Bridge Inventory. Roughly 46% are rated “Good,” 35.8% “Fair,” 13.3% “Poor,” and 13.3% are classified as structurally deficient — the federal designation for spans whose deck, superstructure, or substructure has been rated 4 or below on the 0–9 NBI scale. Structurally deficient does not mean unsafe to cross; it means the bridge is on the priority list for repair or replacement.

Inspections in IL are conducted by certified engineers from the state Department of Transportation on a 24-month cycle, and results are reported back to the FHWA each spring. The list below shows every NBI-tracked bridge in the county, sorted by inventory load rating. Use the “Sort by” controls to surface the lowest-rated spans first, and click any row for full inspection history, traffic counts, and condition trends.

Source: FHWA National Bridge Inventory. See methodology for full definitions.

565

Total Bridges

46%

Good

13.3%

Poor

13.3%

Structurally Deficient

Condition Distribution

Good

46% (260)

Fair

35.8% (202)

Poor

13.3% (75)

SD

13.3% (75)

All Bridges (565)

Sort:

TR 175B SEC 102

Over: PRAIRIE CREEK

.4MI E LAHOGUE, Iroquois, IL

Built 1955 Load: 25.9 t ADT: 75

TR 14

Over: TRIB SPRING CREEK

.2N ILL54 ON CH8, Iroquois, IL

Built 1972 Load: 26.2 t ADT: 300

FAI-57 SB

Over: BRANCH OF SPRING CR

3.1 MI S ONARGA INT, Iroquois, IL

Built 1968 Load: 26.6 t ADT: 8,750

FAI-57 NB

Over: BRANCH OF SPRING CR

3.1 MI S ONARGA INT, Iroquois, IL

Built 1968 Load: 26.6 t ADT: 8,750

FAI 57 NB

Over: SPRING CREEK

2.41 MI S ONARGA INT, Iroquois, IL

Built 1968 Load: 26.9 t ADT: 8,750

TR 27

Over: TRIB LANGAN CREEK

1.5M N 4.5 W CLIFTON, Iroquois, IL

Built 1970 Load: 26.9 t ADT: 50

TR 331A

Over: TRIB MUD CREEK

2.5 MI E OF ILL 1, Iroquois, IL

Built 1960 Load: 26.9 t ADT: 75

FAI-57 SB

Over: SPRING CREEK

2.41 MI S ONARGA INT, Iroquois, IL

Built 1968 Load: 27.2 t ADT: 8,750

TR 180

Over: WHISKEY CREEK

N EDGE CLAYTONVILLE, Iroquois, IL

Built 1968 Load: 27.5 t ADT: 10

TR 275 A

Over: DRAINAGE DITCH

1 MI N .2 W MILFORD, Iroquois, IL

Built 1971 Load: 27.5 t ADT: 75

TR 210

Over: DRAINAGE DITCH

.5 MI N. CH 7, Iroquois, IL

Built 1916 Load: 28.2 t ADT: 75

TR 290

Over: MARTINTON DITCH#2

1 MI NE MARTINTON, Iroquois, IL

Built 1971 Load: 28.2 t ADT: 150

TR 1

Over: STREAM

2.5 MI NW CHENEYVLE, Iroquois, IL

Built 1965 Load: 28.4 t ADT: 50

FAS 329 CH 10 SA 1

Over: GAY CREEK

1.32 MI W OLD ILL 1, Iroquois, IL

Built 1961 Load: 28.8 t ADT: 500

TR 157 SEC 110 TR

Over: SPRING CREEK

1 MI N 45&24 .5 MI E, Iroquois, IL

Built 1961 Load: 28.8 t ADT: 75

TR 353A

Over: STREAM

4 MI W ILL RTE 1, Iroquois, IL

Built 1960 Load: 28.8 t ADT: 25

TR 309

Over: TRIB TO MUD CR

3 MI SE MILFORD, Iroquois, IL

Built 1961 Load: 28.8 t ADT: 75

TR 198

Over: DRAINAGE DITCH

3.5 SE JCT 49&52, Iroquois, IL

Built 1967 Load: 29.2 t ADT: 25

TR 76A

Over: TRIB TO PIGEON CR

.2MI N CH 10 ON CH46, Iroquois, IL

Built 1976 Load: 29.2 t ADT: 50

TR 331

Over: PIGEON CR

1.25 MI E SBI 49, Iroquois, IL

Built 1965 Load: 29.5 t ADT: 50

TR 77

Over: PRAIRIE CR

3 MI E. OF ASHKUM, Iroquois, IL

Built 1970 Load: 29.5 t ADT: 50

TR 31

Over: BEAVER CR

3 MI E BEAVERVILLE, Iroquois, IL

Built 1972 Load: 29.5 t ADT: 75

FAS 335 CH 10

Over: DRAINAGE DITCH

2.5 S 1.6 W CISNA P, Iroquois, IL

Built 1979 Load: 29.5 t ADT: 350

TR 313

Over: SPRING CREEK

4 MI E BUCKLEY, Iroquois, IL

Built 1958 Load: 29.8 t ADT: 25

TR 61

Over: N MARTINTON #2

2.5 SW MARTINTON, Iroquois, IL

Built 1965 Load: 29.8 t ADT: 75

TR 422

Over: BEAVER CR

.5 N CH 3, Iroquois, IL

Built 1957 Load: 30.1 t ADT: 25

TR 95

Over: TRIB. PRAIRIE CR

3 MI NE OF DANFORTH, Iroquois, IL

Built 1973 Load: 30.1 t ADT: 25

TR 363A

Over: GAY CREEK

.8MI W ILL 1, Iroquois, IL

Built 1963 Load: 30.1 t ADT: 125

TR 22B

Over: LOUIS CREEK

1 MI N 1.5 W BUCKLEY, Iroquois, IL

Built 1997 Load: 30.5 t ADT: 25

TR 164

Over: SHAVETAIL CR

0.25 MI N. CH 47, Iroquois, IL

Built 1939 Load: 30.5 t ADT: 25

TR 374

Over: COON CREEK

3.5 MI E. RTE 1, Iroquois, IL

Built 1974 Load: 30.5 t ADT: 25

TR 170

Over: MUD CREEK

2.3 MI N OF CH 10, Iroquois, IL

Built 1976 Load: 30.8 t ADT: 100

TR 442

Over: TRIB TO IROQUOIS RV

2.75 MI S IROQUOIS, Iroquois, IL

Built 1966 Load: 30.8 t ADT: 75

TR 290

Over: MAIN MARTINTON DITCH

1.5 E MARTINTON, Iroquois, IL

Built 1962 Load: 30.8 t ADT: 150

TR 363

Over: WHISKEY CR

2.59 MI E OF ILL 49, Iroquois, IL

Built 1975 Load: 31.4 t ADT: 100

TR 178

Over: PRAIRIE CR

.5 MI N. OF L'ERABLE, Iroquois, IL

Built 1972 Load: 31.8 t ADT: 175

TR 458

Over: BEAVER CR

.5 MI N CH 3, Iroquois, IL

Built 1971 Load: 31.8 t ADT: 25

TR 189

Over: BR OF SPRING CREEK

1.75MI E JCT45&24, Iroquois, IL

Built 1928 Load: 31.8 t ADT: 325

CH 2

Over: TRIB IROQUOIS RIVER

2MI W ILL 1 ON CH 2, Iroquois, IL

Built 1975 Load: 31.8 t ADT: 250

CH 29

Over: LANGAN CR

1.5 MI W 1.5 N CLIFT, Iroquois, IL

Built 1975 Load: 32.1 t ADT: 200

FAI-57 SB

Over: IC RR

8.98 MI S ASHKUM INT, Iroquois, IL

Built 1967 Load: 32.4 t ADT: 9,050

FAI-57 NB

Over: T. P. & W RR

8.78 MI S ASHKUM INT, Iroquois, IL

Built 1967 Load: 32.4 t ADT: 9,050

FAI-57 SB

Over: T.P. & W RR

8.76 MI S ASHKUM INT, Iroquois, IL

Built 1967 Load: 32.4 t ADT: 9,050

US 24

Over: DRAINAGE DITCH

2.1 MILES E OF US 45, Iroquois, IL

Built 1954 Load: 32.4 t ADT: 2,900

FAI-57

Over: STREAM

1.75 MI N OF FORD CO, Iroquois, IL

Built 1971 Load: 32.4 t ADT: 17,600

US 45

Over: CREEK

1.5 M N LODA, Iroquois, IL

Built 1993 Load: 32.4 t ADT: 2,100

FAI-57

Over: LOUIS CREEK

0.89 M.S BUCKLEY INT, Iroquois, IL

Built 2002 Load: 32.4 t ADT: 8,800

TR 269

Over: BR OF SPRING CK

2MI S THAWVILLE, Iroquois, IL

Built 1977 Load: 32.4 t ADT: 25

TR 307

Over: SPRING CREEK

1.2MI E US45 BUCKLEY, Iroquois, IL

Built 1980 Load: 32.4 t ADT: 50

TR 269A

Over: SPRING CREEK

1.5MI S 1MI E DELREY, Iroquois, IL

Built 1983 Load: 32.4 t ADT: 50

Read our methodology — how this data is sourced, computed, and verified.

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Data sourced from official U.S. government datasets. See our methodology for details. Retrieved and formatted by PlainBridges Editorial

Reviewed byPlainbridges Editorial, Plain Bridges Editorial Team · June 6, 2026