County profile · official public datasets

St. Clair County, AL

183 public highway bridges tracked in the FHWA National Bridge Inventory: 27.3% rated Good, 71% Fair, 1.6% Poor.

183
Public bridges: 27.3%
Good condition: 1.6%
Poor condition

The verdict

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

St. Clair County pairs a better-than-median Poor-condition share among rated counties in the state with an older average build year than the state inventory.

Top 33%
lowest Poor share in state: 1.6%
Poor-condition share: 183
public highway bridges: 1967
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.

St. Clair County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, St. Clair County ranks #22 of 67 Alabama counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 1.6%). St. Clair County, Alabama contains 183 public highway bridges. Roughly 27.3% are rated “Good,” 71% “Fair,” and 1.6% “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

183

Public highway bridges in St. Clair County

Good condition

27.3%

50 of 183 rated 7-9

Fair condition

71%

130 of 183 rated 5-6

Poor condition

1.6%

3 of 183 rated 4 or below

In-state Poor-share rank

#22 of 67

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

Condition distribution

Share of 183 NBI-tracked bridges by lowest applicable component rating.

Good

27.3% (50)

Fair

71% (130)

Poor

1.6% (3)

St. Clair County's Poor-condition bridges carry 21,180 vehicle crossings a day

That is 1.5% of the county's reported daily bridge traffic on 1.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 7,060 crossings a day against 5,976 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 183 of 183 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

69.4% of St. Clair County's bridges have passed the 50-year mark

127 of the 183 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 27.3% 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 50% of the county's Poor-condition bridge traffic

I - 59 SOUTH over CANOE CREEK, built 1961, carries 10,585 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 21,180 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1920s

9
1930s

4
1940s

30
1950s

8
1960s

73
1970s

8
1980s

10
1990s

18
2000s

15
2010s

7
2020s

1

What this shows Construction peaked in the 1960s, when 73 of the county's bridges still in the inventory were built, which is 39.9% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year is 1967, 7 years older than the Alabama average of 1974.

How St. Clair County compares with Alabama's closest counties by inventory size

The 5 Alabama counties nearest St. Clair County in number of bridges, with their condition splits. Its 1.6% Poor share is the 3rd-lowest of these 6. Its average build year of 1967 against a peer-group mean of 1970 is in line with the group.

Showing the 5 closest of 66 Alabama counties eligible for comparison.

Bridge inventory size and condition shares for St. Clair County and the 5 Alabama counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Butler County	189	27%	72%	1.1%	1976
Fayette County	186	30.6%	68.3%	1.1%	1969
Chambers County	185	51.9%	40%	8.1%	1973
St. Clair County (this page)	183	27.3%	71%	1.6%	1967
Lamar County	181	26%	71.8%	2.2%	1966
Blount County	180	12.8%	79.4%	7.8%	1968

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 St. Clair 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 St. Clair County, both outside Alabama so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside AL (183 bridges here).

Richmond County, GA · 183 bridges
Marshall County, IN · 183 bridges
Appanoose County, IA · 183 bridges
Keokuk County, IA · 183 bridges

Similar average build year

Nearest mean year-built outside AL (1967 here).

Los Angeles County, CA · avg 1967 · 3,547 bridges
Allegheny County, PA · avg 1967 · 1,294 bridges
Sonoma County, CA · avg 1967 · 609 bridges
Merced County, CA · avg 1967 · 528 bridges

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

All 183 Good 50 Fair 130 Poor 3

Fair-condition bridges (130)

Sort:

St. Clair County Bridge Snapshot

Condition distribution

St. Clair County's Poor-condition bridges carry 21,180 vehicle crossings a day

69.4% of St. Clair County's bridges have passed the 50-year mark

One structure carries 50% of the county's Poor-condition bridge traffic

How St. Clair County compares with Alabama'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 (130)

ST CLAIR CO 66

CHURCH RD.

DEPOTE ST

ST CLAIR CO HW 86

3 RD AV

ST CLAIR CO 14

ST CLAIR CO 12

I59

AL - 174

ST CLAIR CO 17

AL 174

ST CLAIR CO HWY27

I - 59

ST CLAIR/HWY 120

ST CLAIR CO *

AL - 25 (US 411)

KELLEY CRK RD

AL - 4 (US 78)

ST CLAIR CO HWY 6

ST CLAIR CO 101

ST CLAIR/ HWY127

ST CLAIR CO 64

ST CLAIR CO HW 21

US 231

DAWSON STREET

PINEDALE RD/CR 36

I - 20 WEST

I - 20 EAST

AL - 25 (US 411)

US 231

ST CLAIR CO HWY 1

COUNTY ROAD

ST CLAIR CO 25

ST CLAIR CO HWY 8

CO RD 31

ST CLAIR CO HWY16

AL - 25 (US 411)

I - 59 SOUTH

ST CLAIR CO 26

ST CLAIR CO 26

ST CLAIR CO 26

AL - 25 (US 411)

AL - 174

I - 59 NORTH

I 20

AL - 53 (US 231)

AL - 4 (US 78)

I - 20

I - 59 NORTH

AL 23

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