County profile · official public datasets

Ogle County, IL

377 public highway bridges tracked in the FHWA National Bridge Inventory: 46.2% rated Good, 46.2% Fair, 7.7% Poor.

377
Public bridges: 46.2%
Good condition: 7.7%
Poor condition

The verdict

According to the Federal Highway Administration's 2024 National Bridge Inventory.

Ogle County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.

53rd
of 102 on Poor share: 7.7%
Poor-condition share: 377
public highway bridges: 1981
avg year built

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.

Ogle County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Ogle County ranks #53 of 102 Illinois counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 7.7%). Ogle County, Illinois contains 377 public highway bridges. Roughly 46.2% are rated “Good,” 46.2% “Fair,” and 7.7% “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

377

Public highway bridges in Ogle County

Good condition

46.2%

174 of 377 rated 7-9

Fair condition

46.2%

174 of 377 rated 5-6

Poor condition

7.7%

29 of 377 rated 4 or below

In-state Poor-share rank

#53 of 102

Among Illinois counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 377 NBI-tracked bridges by lowest applicable component rating.

Good

46.2% (174)

Fair

46.2% (174)

Poor

7.7% (29)

Ogle County's Poor-condition bridges carry 11,200 vehicle crossings a day

That is 1.4% of the county's reported daily bridge traffic on 7.7% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 386 crossings a day against 906 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 377 of 377 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

32.4% of Ogle County's bridges have passed the 50-year mark

122 of the 377 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 46.2% 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.

One structure carries 15.6% of the county's Poor-condition bridge traffic

LAKEVIEW DRIVE over KYTE CREEK, built 1963, carries 1,750 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 29-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 11,200 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1920s

5
1930s

9
1940s

4
1950s

31
1960s

38
1970s

57
1980s

100
1990s

70
2000s

39
2010s

20
2020s

4

What this shows Construction peaked in the 1980s, when 100 of the county's bridges still in the inventory were built, which is 26.5% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1981) matches the Illinois average (1979).

How Ogle County compares with Illinois's closest counties by inventory size

The 5 Illinois counties nearest Ogle County in number of bridges, with their condition splits. Its 7.7% Poor share is the 2nd-lowest of these 6. Its average build year of 1981 against a peer-group mean of 1979 is in line with the group.

Showing the 5 closest of 101 Illinois counties eligible for comparison.

Bridge inventory size and condition shares for Ogle County and the 5 Illinois counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Ogle County (this page)	377	46.2%	46.2%	7.7%	1981
Bureau County	375	41.3%	43.5%	15.2%	1978
Lee County	371	39.9%	48%	12.1%	1980
Tazewell County	358	25.4%	60.1%	14.5%	1976
Fayette County	357	56.6%	38.4%	5%	1976
Peoria County	352	24.1%	57.7%	18.2%	1983

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 Ogle County's. Source: FHWA National Bridge Inventory, 2024 release.

Nationwide counties with similar inventory size or average build year

Two NBI-derived peer sets for Ogle County, both outside Illinois so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside IL (377 bridges here).

Monterey County, CA · 377 bridges
Cass County, MO · 377 bridges
Butler County, OH · 377 bridges
Butler County, PA · 378 bridges

Similar average build year

Nearest mean year-built outside IL (1981 here).

Franklin County, OH · avg 1981 · 922 bridges
Greenville County, SC · avg 1981 · 635 bridges
Montgomery County, OH · avg 1981 · 632 bridges
Shawnee County, KS · avg 1981 · 563 bridges

Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.

All 377 Good 174 Fair 174 Poor 29

Fair-condition bridges (174)

Sort:

Ogle County Bridge Snapshot

Condition distribution

Ogle County's Poor-condition bridges carry 11,200 vehicle crossings a day

32.4% of Ogle County's bridges have passed the 50-year mark

One structure carries 15.6% of the county's Poor-condition bridge traffic

How Ogle County compares with Illinois's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

Fair-condition bridges (174)

TR-191 (HOLCOMB RD

HOLCOMB RD

BIG MOUND RD.

UNNAMED RDAD (TR)D

HALDANE RD.

WILLOUGHBY RD

LANARK ROAD

MERIDIAN RD

PEEK HOME RD

CONGER RD

FOWLER RD

RAZORVILLE ROAD

BETHEL RD.

SPRING CREEK RD.

BUFFALO RD

OAK GROVE RD

LEAF RIVER RD

COLUMBIAN RD

HOISINGTON ROAD

FORK CREEK RD

MARSH RD.

BUFFALO RD.

TOWNLINE RD.

LEAF RIVER RD.

GRIST MILL RD.

OAK GROVE ROAD

DEVILS BACKBONE RD

COTTONWOOD RD.

TOWN LINE RD.

STILLMAN ROAD

FREEPORT RD

EDGEWOOD ROAD

ROCKY HOLLOW RD

WOODLAWN RD

HOLCOMB RD

BROOKVILLE ROAD

I-88 EB E-W TOLLWA

I-88 WB E-W TOLLWA

VALENTINE ROAD

MONTAGUE ROAD

COFFMAN RD

ADELINE RD

STEWARD RD (FAU545

CHANA RD

RIDGE RD (FAS 85)

FLAGG ROAD

ADELINE RD

FREEPORT RD

FREEPORT ROAD

EAGLE POINT RD

Related