Total bridges
1,721
Public highway bridges in Cook County
County profile · official public datasets
1,721 public highway bridges tracked in the FHWA National Bridge Inventory: 28.8% rated Good, 57.5% Fair, 13.8% Poor.
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Cook County pairs a higher-than-median Poor-condition share among rated counties in the state with an older average build year than the state inventory.
Poor is an FHWA condition category from the lowest applicable component rating (4 or below), not a live crossing-safety or closure decision. Rankings cover counties with at least five public highway bridges.
According to the Federal Highway Administration's 2024 National Bridge Inventory, Cook County ranks #88 of 102 Illinois counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 13.8%). Cook County, Illinois contains 1,721 public highway bridges. Roughly 28.8% are rated “Good,” 57.5% “Fair,” and 13.8% “Poor.” Poor means the lowest applicable deck, superstructure, substructure, or culvert rating is 4 or below on the 0–9 NBI scale. It is a condition category, not a live safety or closure decision.
Responsible agencies inspect covered bridges on risk-based intervals under current NBIS rules and submit inventory data to FHWA annually. The list below shows every NBI-tracked bridge in the county. Use the “Sort by” controls to change the ordering, and click any row for its reported inspection date, traffic count, and condition fields.
Source: FHWA National Bridge Inventory. See methodology for full definitions.
Total bridges
1,721
Public highway bridges in Cook County
Good condition
28.8%
495 of 1,721 rated 7-9
Fair condition
57.5%
989 of 1,721 rated 5-6
Poor condition
13.8%
237 of 1,721 rated 4 or below
In-state Poor-share rank
#88 of 102
Among Illinois counties with 5+ bridges, lower share ranks better
Share of 1,721 NBI-tracked bridges by lowest applicable component rating.
That is 10% of the county's reported daily bridge traffic on 13.8% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 24,743 crossings a day against 30,089 for a Good-condition one. A Poor rating is a condition category, not a closure or a live safety judgement; it means the lowest applicable component rating is 4 or below.
Computed over the 1,714 of 1,721 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
1,130 of the 1,721 bridges with a recorded construction year were built in 1974 or earlier. Age alone is not a defect: a well-maintained older bridge can rate Good, and 28.8% of this county's inventory does. Even so, this older cohort is the population from which future Poor ratings are drawn, which is why the age profile below matters alongside the condition split above.
Cutoff derives from the 2024 release year minus a 50-year design life. Source: FHWA National Bridge Inventory, 2024 release.
I- 90 94 RYAN ELEV over CANAL TO STEWART STS, built 1962, carries 256,900 vehicles a day, the most of any Poor-rated structure here. The county's Poor-condition exposure is concentrated rather than evenly spread, so the 237-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 5,864,125 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
1,721 bridges with a recorded construction year, grouped by decade
Built before 1900
2 bridges
1900–1909
28 bridges
1910–1919
20 bridges
1920–1929
99 bridges
1930–1939
107 bridges
1940–1949
66 bridges
1950–1959
446 bridges
1960–1969
315 bridges
1970–1979
71 bridges
1980–1989
90 bridges
1990–1999
150 bridges
2000–2009
145 bridges
2010–2019
144 bridges
2020–2029
38 bridges
What this shows Construction peaked in the 1950s, when 446 of the county's bridges still in the inventory were built, which is 25.9% of those with a recorded year. That cohort is now 65 to 74 years old in the 2024 inventory. Its average build year is 1969, 10 years older than the Illinois average of 1979.
The 5 Illinois counties nearest Cook County in number of bridges, with their condition splits. Its 13.8% Poor share is the 5th-lowest of these 6. Its average build year of 1969 against a peer-group mean of 1981 is 12 years older.
Showing the 5 closest of 101 Illinois counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Cook County (this page) | 1,721 | 28.8% | 57.5% | 13.8% | 1969 |
| Champaign County | 727 | 58.9% | 32.5% | 8.7% | 1982 |
| Will County | 649 | 43.1% | 46.4% | 10.5% | 1983 |
| McLean County | 624 | 60.9% | 36.2% | 2.9% | 1981 |
| Livingston County | 579 | 51.8% | 39.9% | 8.3% | 1978 |
| Iroquois County | 570 | 46.5% | 39.1% | 14.4% | 1980 |
Each share is of that county's own total tracked bridges; peers are the counties with 5 or more bridges whose inventory size is closest to Cook County's. Source: FHWA National Bridge Inventory, 2024 release.
Two NBI-derived peer sets for Cook County, both outside Illinois so the neighborhoods are not the same-state size table above.
Nearest county inventories outside IL (1,721 bridges here).
Nearest mean year-built outside IL (1969 here).
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Over: CC&P RR
0.15M N ILL 56, Cook, IL
Over: N BR CHICAGO RIV CAN
829 W DIVISION, Cook, IL
Over: SALT CREEK
0.01 W WINSTON DR, Cook, IL
Over: WILSON AVENUE
4600 N & 732 W, Cook, IL
Over: WELLER CR
0.24 M N ILL 58 P5, Cook, IL
Over: N SHORE CHANNEL
2.5 M N ILL 58 P12, Cook, IL
Over: MARLEY CR
0.5 M N 167TH, Cook, IL
Over: WELLER CR
0.5 M N ILL 58 P5, Cook, IL
Over: SPRING CREEK
4 M W IL 59, Cook, IL
Over: MIDLOTHIAN CREEK
0.1 MI. N 171ST ST, Cook, IL
Over: US 45 MANNHEIM RD
0.2 M S OF 111TH ST, Cook, IL
Over: POPLAR CREEK
0.15M. E OF KANE CO., Cook, IL
Over: ADDISON CR TRIB
0.08 M N NORTH P9, Cook, IL
Over: DTCH TO CAL RIV
WOLF LAKE CONS P8C, Cook, IL
Over: RR - CN
0.1 M S I-55, Cook, IL
Over: I- 94 EDENS
4 M N US 14, Cook, IL
Over: NORTH CREEK
0.9 M S 186th, Cook, IL
Over: BUFFALO CREEK TRIB
.82 S OF LAKE COOK R, Cook, IL
Over: S BR CHICAGO RIVER
600 S & 322 W, Cook, IL
Over: LASALLE DR
1700 N & LSD, Cook, IL
Over: ROOSEVELT R (ILL 38)
0.5 M S ILL 5 P20, Cook, IL
Over: I-80/294
2.0 M W OF IL-1, Cook, IL
Over: POPLAR CREEK
0.4 M N BODE RD P7, Cook, IL
Over: LAKE SHORE DRIVE
3900S 926E, Cook, IL
Over: CREEK
WEST OF SHERIDAN, Cook, IL
Over: FLAG CREEK
0.02 M E WOLF P10, Cook, IL
Over: WELLERS DRN DTCH
0.16 M E BUSSE RDP5, Cook, IL
Over: UNION STATION TRACKS
400S 400W TO 500W, Cook, IL
Over: MIDLOTHIAN CREEK
0.5 M E CRAWFORD AV, Cook, IL
Over: THORN CREEK
0.6 M W ASHLAND P2, Cook, IL
Over: LOWER LEVEL
300N 154E TO 300E, Cook, IL
Over: RANDOLPH ST & LAND
500E.& 340N.TO 130N., Cook, IL
Over: MS-6001 Lw Lv Term
T3 (SPANS 25X-36)ORD, Cook, IL
Over: HIGGINS CREEK
2.9 M W US 45, Cook, IL
Over: ALONG US 6 EB LANES
FROM I57 TO I294, Cook, IL
Over: US12 20 41 INDIANAPO
0.03 M NW 106TH, Cook, IL
Over: BUTTERFIELD CREEK
0.7M E. KEDZIE AV, Cook, IL
Over: I- 80 EB
3.1 M S US 6, Cook, IL
Over: FULLERTON AVENUE
2400N 100W, Cook, IL
Over: CAL SG CHNL&RR&BRDWY
1.5 M N IL 83, Cook, IL
Over: CAL SAG CHANNEL
0.2 N BROADWAY P26, Cook, IL
Over: RANDOLPH ST.& LAND
500E.& 340N.TO 130N., Cook, IL
Over: N SHORE CHANNEL
EVANSTON P6, Cook, IL
Over: TINLEY CREEK
1.64M.W.OF HARLEM AV, Cook, IL
Over: CALUMET-UNION DRAIN
300 FT. E. OF I-294, Cook, IL
Over: SALT CR
0.5 E PLUM GR P18, Cook, IL
Over: PEDESTRIAN UNDERPASS
3100N & 200W, Cook, IL
Over: POPLAR CREEK
0.25 M S I90 P22, Cook, IL
Over: THORN CREEK
0.5 M E ASHLND P2, Cook, IL
Over: GROUND SE INDIANA AV
0.08 M NW MARQ RDP7C, Cook, IL
Read our methodology - how this data is sourced, computed, and verified.
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.