County profile · official public datasets

Calhoun County, IL

81 public highway bridges tracked in the FHWA National Bridge Inventory: 53.1% rated Good, 43.2% Fair, 3.7% Poor.

81
Public bridges: 53.1%
Good condition: 3.7%
Poor condition

The verdict

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

Calhoun County posts a top-10% lowest Poor-condition share among rated counties in the state across rated county bridge inventory.

Top 9%
lowest Poor share in state: 3.7%
Poor-condition share: 81
public highway bridges: 1983
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.

Calhoun County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Calhoun County ranks #9 of 102 Illinois counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 3.7%). Calhoun County, Illinois contains 81 public highway bridges. Roughly 53.1% are rated “Good,” 43.2% “Fair,” and 3.7% “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

Public highway bridges in Calhoun County

Good condition

53.1%

43 of 81 rated 7-9

Fair condition

43.2%

35 of 81 rated 5-6

Poor condition

3.7%

3 of 81 rated 4 or below

In-state Poor-share rank

#9 of 102

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

Condition distribution

Share of 81 NBI-tracked bridges by lowest applicable component rating.

Good

53.1% (43)

Fair

43.2% (35)

Poor

3.7% (3)

Calhoun County's Poor-condition bridges carry 300 vehicle crossings a day

That is 0.8% of the county's reported daily bridge traffic on 3.7% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 100 crossings a day against 558 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 81 of 81 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

23.5% of Calhoun County's bridges have passed the 50-year mark

19 of the 81 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 53.1% 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 75% of the county's Poor-condition bridge traffic

FAS 755 (CH2) over IRISH HOLLOW CREEK, built 1977, carries 225 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 3-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 300 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

5
1930s

7
1940s

3
1950s

3
1960s

1
1970s

3
1980s

9
1990s

24
2000s

13
2010s

13

What this shows Construction peaked in the 1990s, when 24 of the county's bridges still in the inventory were built, which is 29.6% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year (1983) matches the Illinois average (1979).

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

The 5 Illinois counties nearest Calhoun County in number of bridges, with their condition splits. Its 3.7% Poor share is the 1st-lowest of these 6. Its average build year of 1983 against a peer-group mean of 1983 is in line with the group.

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

Bridge inventory size and condition shares for Calhoun County and the 5 Illinois counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Pope County	88	63.6%	29.5%	6.8%	1983
Mason County	86	33.7%	61.6%	4.7%	1980
Gallatin County	82	78%	13.4%	8.5%	1984
Calhoun County (this page)	81	53.1%	43.2%	3.7%	1983
Edwards County	79	64.6%	27.8%	7.6%	1982
Cass County	77	29.9%	50.6%	19.5%	1986

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 Calhoun 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 Calhoun County, both outside Illinois so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside IL (81 bridges here).

Berrien County, GA · 81 bridges
Fayette County, GA · 81 bridges
Sumter County, GA · 81 bridges
White County, GA · 81 bridges

Similar average build year

Nearest mean year-built outside IL (1983 here).

Dallas County, TX · avg 1983 · 3,230 bridges
Bexar County, TX · avg 1983 · 2,342 bridges
Sedgwick County, KS · avg 1983 · 1,333 bridges
Bernalillo County, NM · avg 1983 · 496 bridges

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

All 81 Good 43 Fair 35 Poor 3

Good-condition bridges (43)

Sort:

Calhoun County Bridge Snapshot

Condition distribution

Calhoun County's Poor-condition bridges carry 300 vehicle crossings a day

23.5% of Calhoun County's bridges have passed the 50-year mark

One structure carries 75% of the county's Poor-condition bridge traffic

How Calhoun 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

Good-condition bridges (43)

ILL 96

ILL 96

TR 75

RIP RAP ROAD TR 2

IL 100

TR 27

FAS 755

TR 19B

TR 13

TR 49

TR 5

TR 27

TR 15 WILCAT HOLLO

TR 15 WILDCAT HOLL

TR 19B

TR 88

TR 2 PLSNT HILL AC

TR 21 PLEASANT DAL

TR 90

TR 90

TR 105

TR 30

TR 15

TR 90

TR 76

TR 90

TR 96A

TR 17

ILL 100

ILLINOIS 100

IL 100

ILL 100

TR 93

ILL 96

ILL 96

ILL 96

ILL 96

FAS 754

IL 96

PARK ST IN HARDIN

ILL 96

ILL 100

IL 100

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