County profile · official public datasets

Hamilton County, TN

464 public highway bridges tracked in the FHWA National Bridge Inventory: 46.8% rated Good, 47% Fair, 6.3% Poor.

Compiled by PlainBridges

464
Public bridges: 46.8%
Good condition: 6.3%
Poor condition

The verdict

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

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

74th
of 95 on Poor share: 6.3%
Poor-condition share: 464
public highway bridges: 1976
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.

Hamilton County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Hamilton County ranks #74 of 95 Tennessee counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 6.3%). Hamilton County, Tennessee contains 464 public highway bridges. Roughly 46.8% are rated “Good,” 47% “Fair,” and 6.3% “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

464

Public highway bridges in Hamilton County

Good condition

46.8%

217 of 464 rated 7-9

Fair condition

47%

218 of 464 rated 5-6

Poor condition

6.3%

29 of 464 rated 4 or below

In-state Poor-share rank

#74 of 95

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

Condition distribution

Share of 464 NBI-tracked bridges by lowest applicable component rating.

Good

46.8% (217)

Fair

47% (218)

Poor

6.3% (29)

Hamilton County's Poor-condition bridges carry 848,351 vehicle crossings a day

That is 6.3% of the county's reported daily bridge traffic on 6.3% of its bridges: Poor-condition structures carry the same share of traffic than their share of the inventory. Each Poor bridge averages 29,253 crossings a day against 27,060 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 464 of 464 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

45.7% of Hamilton County's bridges have passed the 50-year mark

212 of the 464 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 46.8% 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 13.6% of the county's Poor-condition bridge traffic

I24 EBL & WBL over BRANCH, built 1960, carries 115,412 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 29-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 848,351 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

1
1910s

2
1920s

14
1930s

31
1940s

16
1950s

42
1960s

88
1970s

52
1980s

69
1990s

59
2000s

32
2010s

25
2020s

33

What this shows Construction peaked in the 1960s, when 88 of the county's bridges still in the inventory were built, which is 19% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1976) matches the Tennessee average (1977).

How Hamilton County compares with Tennessee's closest counties by inventory size

The 5 Tennessee counties nearest Hamilton County in number of bridges, with their condition splits. Its 6.3% Poor share is the 4th-lowest of these 6. Its average build year of 1976 against a peer-group mean of 1978 is in line with the group.

Showing the 5 closest of 94 Tennessee counties eligible for comparison.

Bridge inventory size and condition shares for Hamilton County and the 5 Tennessee counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Williamson County	520	63.5%	33.1%	3.5%	1984
Hamilton County (this page)	464	46.8%	47%	6.3%	1976
Rutherford County	428	60.3%	35.5%	4.2%	1977
Maury County	424	22.9%	70.8%	6.4%	1975
Madison County	418	31.8%	64.1%	4.1%	1983
Wilson County	402	60.7%	31.1%	8.2%	1972

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

Similar inventory size

Nearest county inventories outside TN (464 bridges here).

Jefferson County, CO · 464 bridges
Calcasieu County, LA · 463 bridges
Darke County, OH · 463 bridges
Anderson County, SC · 463 bridges

Similar average build year

Nearest mean year-built outside TN (1976 here).

Marion County, IN · avg 1976 · 958 bridges
Mohave County, AZ · avg 1976 · 641 bridges
Comanche County, OK · avg 1976 · 593 bridges
Prince George's County, MD · avg 1976 · 576 bridges

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

All 464 Good 217 Fair 218 Poor 29

All bridges (464)

Sort:

Hamilton County Bridge Snapshot

Condition distribution

Hamilton County's Poor-condition bridges carry 848,351 vehicle crossings a day

45.7% of Hamilton County's bridges have passed the 50-year mark

One structure carries 13.6% of the county's Poor-condition bridge traffic

How Hamilton County compares with Tennessee's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

All bridges (464)

FAP 29

NB RP TO FAU 1126

NB RP FRM FAU 1126

FAP 29

FAP 29

FAP 29

FAP 29

FAP 29

FAP 29

FAP 29

FAP 29

FAP 29

FAP 29 / FAU 3634

FAU 38

FAU A342

FAS 60

NFA D546

FAU 148

FAU 3602

FAU 3556

FAU 317

SR317

SR 317

FAU 319

FAU 4976

FAP 153 RP

FAU 4133

FAP 153

FAU 319

I24 WB RP TO I124N

FAU 3601

FAU 4148

FAP 111/FAP 29 SBL

I24 EBL

I24 WBL

FAU 3604

FAU 4144

NFA E008 (SA 3327)

FAU 4470 (SA 3305)

FAU 3599 350044P

NFA E260

FAU 3633 841976T

NFA 2162 (SA 3308)

FAU 2

FAU 3556 350045W

FAU 3556 350045W

FAU 2 350056J

NFA B323

FAU 8

FAU 3615

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