County profile · official public datasets

DeKalb County, TN

100 public highway bridges tracked in the FHWA National Bridge Inventory: 23% rated Good, 70% Fair, 7% Poor.

100
Public bridges: 23%
Good condition: 7%
Poor condition

The verdict

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

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

80th
of 95 on Poor share: 7%
Poor-condition share: 100
public highway bridges: 1977
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.

DeKalb County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, DeKalb County ranks #80 of 95 Tennessee counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 7%). DeKalb County, Tennessee contains 100 public highway bridges. Roughly 23% are rated “Good,” 70% “Fair,” and 7% “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

100

Public highway bridges in DeKalb County

Good condition

23%

23 of 100 rated 7-9

Fair condition

70%

70 of 100 rated 5-6

Poor condition

7 of 100 rated 4 or below

In-state Poor-share rank

#80 of 95

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

Condition distribution

Share of 100 NBI-tracked bridges by lowest applicable component rating.

Good

23% (23)

Fair

70% (70)

Poor

7% (7)

DeKalb County's Poor-condition bridges carry 9,929 vehicle crossings a day

That is 5.6% of the county's reported daily bridge traffic on 7% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 1,418 crossings a day against 1,044 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 100 of 100 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

40% of DeKalb County's bridges have passed the 50-year mark

40 of the 100 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 23% 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 66.2% of the county's Poor-condition bridge traffic

FAP 56 over FALL CREEK, built 1971, carries 6,573 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 7-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 9,929 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1920s

1
1930s

1
1940s

12
1950s

13
1960s

3
1970s

17
1980s

31
1990s

8
2000s

6
2010s

6
2020s

2

What this shows Construction peaked in the 1980s, when 31 of the county's bridges still in the inventory were built, which is 31% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1977) matches the Tennessee average (1977).

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

The 5 Tennessee counties nearest DeKalb County in number of bridges, with their condition splits. Its 7% Poor share is the 6th-lowest of these 6. Its average build year of 1977 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 DeKalb County and the 5 Tennessee counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Scott County	111	24.3%	71.2%	4.5%	1973
Johnson County	109	44%	51.4%	4.6%	1972
Decatur County	104	35.6%	63.5%	1%	1982
Rhea County	100	34%	59%	7%	1979
DeKalb County (this page)	100	23%	70%	7%	1977
Claiborne County	98	35.7%	60.2%	4.1%	1985

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

Similar inventory size

Nearest county inventories outside TN (100 bridges here).

Ketchikan Gateway County, AK · 100 bridges
Gunnison County, CO · 100 bridges
Monroe County, FL · 100 bridges
Fayette County, IN · 100 bridges

Similar average build year

Nearest mean year-built outside TN (1977 here).

San Diego County, CA · avg 1977 · 1,632 bridges
King County, WA · avg 1977 · 1,238 bridges
Riverside County, CA · avg 1977 · 1,117 bridges
Contra Costa County, CA · avg 1977 · 618 bridges

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

All 100 Good 23 Fair 70 Poor 7

Good-condition bridges (23)

Sort:

DeKalb County Bridge Snapshot

Condition distribution

DeKalb County's Poor-condition bridges carry 9,929 vehicle crossings a day

40% of DeKalb County's bridges have passed the 50-year mark

One structure carries 66.2% of the county's Poor-condition bridge traffic

How DeKalb 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 (23)

NFA A219 (SA 2107)

FAP 56

NFA A327

NFA A054

NFA 2148 (SA 2119)

NFA 2149 (SA 2111)

NFA 2191 (SA 2102)

NFA A018

NFA A016

NFA A012

NFA A095

NFA A299 (SA 2102)

NFA A301

NFA A347

NFA A330

NFA A368

NFA A052

NFA A381

FAP 56

FAP 56

FAS 96

NFA A417

NFA A288

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