County profile · official public datasets

Polk County, TN

140 public highway bridges tracked in the FHWA National Bridge Inventory: 55% rated Good, 37.1% Fair, 7.9% Poor.

140
Public bridges: 55%
Good condition: 7.9%
Poor condition

The verdict

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

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

84th
of 95 on Poor share: 7.9%
Poor-condition share: 140
public highway bridges: 1979
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.

Polk County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Polk County ranks #84 of 95 Tennessee counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 7.9%). Polk County, Tennessee contains 140 public highway bridges. Roughly 55% are rated “Good,” 37.1% “Fair,” and 7.9% “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

140

Public highway bridges in Polk County

Good condition

55%

77 of 140 rated 7-9

Fair condition

37.1%

52 of 140 rated 5-6

Poor condition

7.9%

11 of 140 rated 4 or below

In-state Poor-share rank

#84 of 95

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

Condition distribution

Share of 140 NBI-tracked bridges by lowest applicable component rating.

Good

55% (77)

Fair

37.1% (52)

Poor

7.9% (11)

Polk County's Poor-condition bridges carry 21,962 vehicle crossings a day

That is 7% of the county's reported daily bridge traffic on 7.9% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 1,997 crossings a day against 1,972 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 140 of 140 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

35.7% of Polk County's bridges have passed the 50-year mark

50 of the 140 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 55% 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 38.4% of the county's Poor-condition bridge traffic

FAP 33 347920N over OCOEE RIVER, built 2012, carries 8,437 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 11-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 21,962 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

1
1920s

7
1930s

9
1940s

7
1950s

3
1960s

20
1970s

7
1980s

37
1990s

16
2000s

13
2010s

17
2020s

3

What this shows Construction peaked in the 1980s, when 37 of the county's bridges still in the inventory were built, which is 26.4% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1979) matches the Tennessee average (1977).

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

The 5 Tennessee counties nearest Polk County in number of bridges, with their condition splits. Its 7.9% Poor share is the 5th-lowest of these 6. Its average build year of 1979 against a peer-group mean of 1976 is in line with the group.

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

Bridge inventory size and condition shares for Polk County and the 5 Tennessee counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Benton County	147	33.3%	65.3%	1.4%	1979
Monroe County	145	62.1%	33.8%	4.1%	1976
Polk County (this page)	140	55%	37.1%	7.9%	1979
Campbell County	137	24.8%	71.5%	3.6%	1973
Cumberland County	137	32.8%	48.9%	18.2%	1971
Lewis County	136	19.1%	77.9%	2.9%	1979

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

Similar inventory size

Nearest county inventories outside TN (140 bridges here).

Henry County, GA · 140 bridges
Geary County, KS · 140 bridges
Colfax County, NM · 140 bridges
Harrison County, OH · 140 bridges

Similar average build year

Nearest mean year-built outside TN (1979 here).

Pima County, AZ · avg 1979 · 1,150 bridges
Jefferson County, KY · avg 1979 · 662 bridges
Spartanburg County, SC · avg 1979 · 638 bridges
McPherson County, KS · avg 1979 · 586 bridges

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

All 140 Good 77 Fair 52 Poor 11

Good-condition bridges (77)

Sort:

Polk County Bridge Snapshot

Condition distribution

Polk County's Poor-condition bridges carry 21,962 vehicle crossings a day

35.7% of Polk County's bridges have passed the 50-year mark

One structure carries 38.4% of the county's Poor-condition bridge traffic

How Polk 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

Good-condition bridges (77)

NFA 1223 (SA 7008)

NFA 1223 347887R

NFA 1223 (SA 7008)

NFA 2317 (SA 7015)

FAS 30

FAS 30

FAS 30

FAS 30

FAP 402 347926E

FAP 33 347920N

FAP 33

FAP 33

FAP 33

FAP 33

FAP 402 (SR 40)

FAP 402 (SR 40)

FAP 402 (SR 40)

FAP 402 (SR 40)

FAP 402 (SR 40)

FAP 68

FAP 68 347962A

FAP 68

GRAVEL ROAD

NFSR 108

NFA 2326 (SA 7011)

NFSR 221

NFSR 23

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