County profile · official public datasets

Alexander County, IL

93 public highway bridges tracked in the FHWA National Bridge Inventory: 26.9% rated Good, 64.5% Fair, 8.6% Poor.

93
Public bridges: 26.9%
Good condition: 8.6%
Poor condition

The verdict

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

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

63rd
of 102 on Poor share: 8.6%
Poor-condition share: 93
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.

Alexander County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Alexander County ranks #63 of 102 Illinois counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 8.6%). Alexander County, Illinois contains 93 public highway bridges. Roughly 26.9% are rated “Good,” 64.5% “Fair,” and 8.6% “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 Alexander County

Good condition

26.9%

25 of 93 rated 7-9

Fair condition

64.5%

60 of 93 rated 5-6

Poor condition

8.6%

8 of 93 rated 4 or below

In-state Poor-share rank

#63 of 102

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

Condition distribution

Share of 93 NBI-tracked bridges by lowest applicable component rating.

Good

26.9% (25)

Fair

64.5% (60)

Poor

8.6% (8)

Alexander County's Poor-condition bridges carry 9,825 vehicle crossings a day

That is 8.2% of the county's reported daily bridge traffic on 8.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 1,228 crossings a day against 706 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 93 of 93 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

31.2% of Alexander County's bridges have passed the 50-year mark

29 of the 93 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 26.9% 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 35.1% of the county's Poor-condition bridge traffic

US 60 & 62 over MISSISSIPPI R, built 1929, carries 3,450 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 8-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 9,825 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

1
1920s

1
1930s

3
1940s

3
1950s

4
1960s

11
1970s

16
1980s

23
1990s

14
2000s

10
2010s

6
2020s

1

What this shows Construction peaked in the 1980s, when 23 of the county's bridges still in the inventory were built, which is 24.7% 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 Alexander County compares with Illinois's closest counties by inventory size

The 5 Illinois counties nearest Alexander County in number of bridges, with their condition splits. Its 8.6% Poor share is the 5th-lowest of these 6. Its average build year of 1981 against a peer-group mean of 1982 is in line with the group.

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

Bridge inventory size and condition shares for Alexander County and the 5 Illinois counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Scott County	99	54.5%	38.4%	7.1%	1983
Stark County	93	57%	37.6%	5.4%	1983
Alexander County (this page)	93	26.9%	64.5%	8.6%	1981
Menard County	89	40.4%	49.4%	10.1%	1980
Wabash County	89	61.8%	32.6%	5.6%	1983
Pope County	88	63.6%	29.5%	6.8%	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 Alexander 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 Alexander County, both outside Illinois so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside IL (93 bridges here).

Baker County, FL · 93 bridges
Banks County, GA · 93 bridges
Haralson County, GA · 93 bridges
Cumberland County, KY · 93 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 93 Good 25 Fair 60 Poor 8

Fair-condition bridges (60)

Sort:

Alexander County Bridge Snapshot

Condition distribution

Alexander County's Poor-condition bridges carry 9,825 vehicle crossings a day

31.2% of Alexander County's bridges have passed the 50-year mark

One structure carries 35.1% of the county's Poor-condition bridge traffic

How Alexander 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 (60)

US 51

TR-58

TR-15

FAS 2943

TR-44

ILLINOIS 127

FAS 946

I 57 SB

OLD IL RTE 3-GALE

ILL 3

TR 16

NO DATA ENTERED

FAI 57

CH-4 (FAS-945)

TR 125

I 57 NB

I 57 SB

TR 16

FAS 2943

TWP RD 41

TR 51

FAP 312-IL 146

TR 73

TR 41A

FAS 945

TR141A

FAS 2943

FAI-57 NB

I 57 SB

TR 123A

FAS 943

MS-1010

I 57 NB

ILL 3

FAP 14-ILL 3

FAS 2943

TR 106

TR 97-DAVIE ROAD

TR 93

TR 98

TR 150A

TR 51

TR 44

TR 39

TR 105-CLANK ROAD

TR 150

TR 105

TR 123A

TR 67

TR 47A

Related