County profile · official public datasets

Bureau County, IL

375 public highway bridges tracked in the FHWA National Bridge Inventory: 41.3% rated Good, 43.5% Fair, 15.2% Poor.

375
Public bridges: 41.3%
Good condition: 15.2%
Poor condition

The verdict

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

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

92nd
of 102 on Poor share: 15.2%
Poor-condition share: 375
public highway bridges: 1978
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.

Bureau County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Bureau County ranks #92 of 102 Illinois counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 15.2%). Bureau County, Illinois contains 375 public highway bridges. Roughly 41.3% are rated “Good,” 43.5% “Fair,” and 15.2% “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

375

Public highway bridges in Bureau County

Good condition

41.3%

155 of 375 rated 7-9

Fair condition

43.5%

163 of 375 rated 5-6

Poor condition

15.2%

57 of 375 rated 4 or below

In-state Poor-share rank

#92 of 102

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

Condition distribution

Share of 375 NBI-tracked bridges by lowest applicable component rating.

Good

41.3% (155)

Fair

43.5% (163)

Poor

15.2% (57)

Bureau County's Poor-condition bridges carry 16,140 vehicle crossings a day

That is 3.1% of the county's reported daily bridge traffic on 15.2% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 283 crossings a day against 1,875 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 374 of 375 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

43.5% of Bureau County's bridges have passed the 50-year mark

163 of the 375 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 41.3% 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 14.9% of the county's Poor-condition bridge traffic

IL 40 FAP 646 over I-80, built 1963, carries 2,400 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 57-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 16,140 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

pre-1900

2
1900s

3
1910s

7
1920s

10
1930s

14
1940s

10
1950s

19
1960s

91
1970s

23
1980s

58
1990s

49
2000s

37
2010s

42
2020s

10

What this shows Construction peaked in the 1960s, when 91 of the county's bridges still in the inventory were built, which is 24.3% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1978) matches the Illinois average (1979).

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

The 5 Illinois counties nearest Bureau County in number of bridges, with their condition splits. Its 15.2% Poor share is the 5th-lowest of these 6. Its average build year of 1978 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 Bureau County and the 5 Illinois counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Ogle County	377	46.2%	46.2%	7.7%	1981
Bureau County (this page)	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 Bureau 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 Bureau County, both outside Illinois so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside IL (375 bridges here).

Dickinson County, KS · 375 bridges
Scioto County, OH · 376 bridges
Benton County, IA · 374 bridges
Baltimore city County, MD · 374 bridges

Similar average build year

Nearest mean year-built outside IL (1978 here).

Orange County, CA · avg 1978 · 1,164 bridges
Sumner County, KS · avg 1978 · 659 bridges
Allen County, IN · avg 1978 · 613 bridges
Buncombe County, NC · avg 1978 · 555 bridges

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

All 375 Good 155 Fair 163 Poor 57

Fair-condition bridges (163)

Sort:

Bureau County Bridge Snapshot

Condition distribution

Bureau County's Poor-condition bridges carry 16,140 vehicle crossings a day

43.5% of Bureau County's bridges have passed the 50-year mark

One structure carries 14.9% of the county's Poor-condition bridge traffic

How Bureau 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 (163)

I-180

I-180 NB

I-180 SB

I-80 WB

US 6

IL 89

US 6 FAS 1247

TR 364 (3000E)

US 6

FAS 253/CH 10

I-180 SB

US 34

I-180 NB

6TH STREET

I-80 EB

TR 374

IL 26 & OR 26

IL 92 FAP 587

FAS 1246/CH 24

IL 29

TOWNSHIP ROAD 74

I-80 EB

US 6

IL 92 FAP 587

I-180 SB

I-180 NB

I-180 EB

I-180 NB

I-180 WB

I-180 EB/SB

I-180 NB

TR-281

I-80 EB

I-80 WB

TISKILWA SPUR

US 6/34 FAS 1248

FAS 188A/CH 8

Backbone Rd FAS 24

IL 89

I-180 SB

I-180 NB

IL 29

TOWNSHIP ROAD 74

I-180 EB/SB

TR 241

IL 29/26

IL 26 FAP 615

I-80 EB

I-80 WB

IL 29to I-180NB Ra

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