County profile · official public datasets

Shelby County, AL

344 public highway bridges tracked in the FHWA National Bridge Inventory: 41% rated Good, 58.1% Fair, 0.9% Poor.

344
Public bridges: 41%
Good condition: 0.9%
Poor condition

The verdict

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

Shelby County pairs a top-quartile lowest Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

Top 15%
lowest Poor share in state: 0.9%
Poor-condition share: 344
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.

Shelby County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Shelby County ranks #10 of 67 Alabama counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 0.9%). Shelby County, Alabama contains 344 public highway bridges. Roughly 41% are rated “Good,” 58.1% “Fair,” and 0.9% “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

344

Public highway bridges in Shelby County

Good condition

41%

141 of 344 rated 7-9

Fair condition

58.1%

200 of 344 rated 5-6

Poor condition

0.9%

3 of 344 rated 4 or below

In-state Poor-share rank

#10 of 67

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

Condition distribution

Share of 344 NBI-tracked bridges by lowest applicable component rating.

Good

41% (141)

Fair

58.1% (200)

Poor

0.9% (3)

Shelby County's Poor-condition bridges carry 29,411 vehicle crossings a day

That is 1.2% of the county's reported daily bridge traffic on 0.9% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 9,804 crossings a day against 2,663 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 344 of 344 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

32.3% of Shelby County's bridges have passed the 50-year mark

111 of the 344 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% 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 96.9% of the county's Poor-condition bridge traffic

AL - 3 NORTH over PEAVINE CK * ACL RR, built 1924, carries 28,511 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 29,411 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

1
1920s

15
1930s

23
1940s

4
1950s

32
1960s

26
1970s

42
1980s

39
1990s

53
2000s

82
2010s

21
2020s

6

What this shows Construction peaked in the 2000s, when 82 of the county's bridges still in the inventory were built, which is 23.8% of those with a recorded year. That cohort is now 15 to 24 years old in the 2024 inventory. Its average build year is 1981, 7 years newer than the Alabama average of 1974.

How Shelby County compares with Alabama's closest counties by inventory size

The 5 Alabama counties nearest Shelby County in number of bridges, with their condition splits. Its 0.9% Poor share is the 1st-lowest of these 6. Its average build year of 1981 against a peer-group mean of 1973 is 8 years newer.

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

Bridge inventory size and condition shares for Shelby County and the 5 Alabama counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Calhoun County	386	32.9%	63.2%	3.9%	1969
Baldwin County	381	48.3%	50.4%	1.3%	1991
Shelby County (this page)	344	41%	58.1%	0.9%	1981
Covington County	332	31.9%	63%	5.1%	1970
Limestone County	324	45.1%	52.8%	2.2%	1972
Jackson County	314	29%	67.2%	3.8%	1961

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

Similar inventory size

Nearest county inventories outside AL (344 bridges here).

DuPage County, IL · 344 bridges
Kankakee County, IL · 344 bridges
Cumberland County, ME · 344 bridges
Greene County, OH · 344 bridges

Similar average build year

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

Franklin County, OH · avg 1981 · 922 bridges
Greenville County, SC · avg 1981 · 635 bridges
Montgomery County, OH · avg 1981 · 632 bridges
McLean County, IL · avg 1981 · 624 bridges

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

All 344 Good 141 Fair 200 Poor 3

Fair-condition bridges (200)

Sort:

Shelby County Bridge Snapshot

Condition distribution

Shelby County's Poor-condition bridges carry 29,411 vehicle crossings a day

32.3% of Shelby County's bridges have passed the 50-year mark

One structure carries 96.9% of the county's Poor-condition bridge traffic

How Shelby 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 (200)

CO RD 67

I - 65 SOUTH

AL - 3 SOUTH

CO. HWY. 59

I - 65 SOUTH

I - 65 NORTH

CO. HWY. 43

CO. HWY. 280

CO. HWY. 280

FOREST LAKES BLVD

CR 266

AL - 38 WEST

CO. HWY. 10

I - 65 SOUTH

I - 65 NORTH

CO. HWY. 280

HIDDEN RIDGE DRIVE

CO. HWY. 280

CO. HWY. 280

CO RD 26

AL - 53 (US 231)

6TH AVE SW

AL - 25

AL - 261

COUNTY ROAD 60

CR 47

CR 47

CR 22

AL - 25

AL - 25

CO. HWY. 211

AL - 3 SOUTH

AL - 70

CO. HWY. 55

Dead Holl. Rd. N

AL - 3 (US 31)

I - 65 SOUTH

I - 65 NORTH

CO.HWY. 275

AL - 145

CO RD 87

AL 25

COUNTY ROAD 26

COMMERCE DRIVE

AL - 25

I - 65 NORTH

CO. HWY. 365

AL - 70

I - 65 SOUTH

I - 65 NORTH

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