County profile · official public datasets

Smith County, TN

202 public highway bridges tracked in the FHWA National Bridge Inventory: 56.4% rated Good, 33.7% Fair, 9.9% Poor.

202
Public bridges: 56.4%
Good condition: 9.9%
Poor condition

The verdict

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

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

90th
of 95 on Poor share: 9.9%
Poor-condition share: 202
public highway bridges: 1971
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.

Smith County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Smith County ranks #90 of 95 Tennessee counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 9.9%). Smith County, Tennessee contains 202 public highway bridges. Roughly 56.4% are rated “Good,” 33.7% “Fair,” and 9.9% “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

202

Public highway bridges in Smith County

Good condition

56.4%

114 of 202 rated 7-9

Fair condition

33.7%

68 of 202 rated 5-6

Poor condition

9.9%

20 of 202 rated 4 or below

In-state Poor-share rank

#90 of 95

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

Condition distribution

Share of 202 NBI-tracked bridges by lowest applicable component rating.

Good

56.4% (114)

Fair

33.7% (68)

Poor

9.9% (20)

Smith County's Poor-condition bridges carry 249,901 vehicle crossings a day

That is 16.1% of the county's reported daily bridge traffic on 9.9% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 12,495 crossings a day against 3,608 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 202 of 202 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

54.5% of Smith County's bridges have passed the 50-year mark

110 of the 202 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 56.4% 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 18% of the county's Poor-condition bridge traffic

I40 349207A over CSX RR & COUNTY ROAD, built 1962, carries 44,898 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 20-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 249,901 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

2
1920s

7
1930s

7
1940s

10
1950s

13
1960s

57
1970s

21
1980s

55
1990s

19
2000s

3
2010s

8

What this shows Construction peaked in the 1960s, when 57 of the county's bridges still in the inventory were built, which is 28.2% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year is 1971, 6 years older than the Tennessee average of 1977.

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

The 5 Tennessee counties nearest Smith County in number of bridges, with their condition splits. Its 9.9% Poor share is the 5th-lowest of these 6. Its average build year of 1971 against a peer-group mean of 1979 is 8 years older.

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

Bridge inventory size and condition shares for Smith County and the 5 Tennessee counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Henderson County	207	31.9%	64.7%	3.4%	1983
Robertson County	204	63.7%	34.8%	1.5%	1975
Smith County (this page)	202	56.4%	33.7%	9.9%	1971
Tipton County	201	40.3%	55.2%	4.5%	1985
Bradley County	199	58.8%	38.7%	2.5%	1975
Carter County	195	44.6%	43.1%	12.3%	1976

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

Similar inventory size

Nearest county inventories outside TN (202 bridges here).

Elmore County, AL · 202 bridges
Clark County, AR · 202 bridges
St. Francis County, AR · 202 bridges
Floyd County, GA · 202 bridges

Similar average build year

Nearest mean year-built outside TN (1971 here).

Wayne County, MI · avg 1971 · 1,026 bridges
Baltimore County, MD · avg 1971 · 783 bridges
Washington County, PA · avg 1971 · 655 bridges
Linn County, OR · avg 1971 · 566 bridges

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

All 202 Good 114 Fair 68 Poor 20

All bridges (202)

Sort:

Smith County Bridge Snapshot

Condition distribution

Smith County's Poor-condition bridges carry 249,901 vehicle crossings a day

54.5% of Smith County's bridges have passed the 50-year mark

One structure carries 18% of the county's Poor-condition bridge traffic

How Smith 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 (202)

NFA 2072 (SA 8009)

NFA 2072 (SA 8009)

NFA 2072 (SA 8009)

NFA 2080

NFA 2081 (SA 8012)

NFA 2081 (SA 8012)

NFA 5574 (SA 8017)

NFA 5574 (SA 8017)

NFA 5574

NFA 2084

NFA A132

NFA A005

NFA A006

NFA A028

NFA A035

NFA A039

NFA A047

NFA A056

NFA A063

NFA A072

NFA A088

NFA A092

NFA A093

NFA A113

NFA A113

NFA A114

NFA A114

NFA A114

NFA A119

NFA A153

NFA A158

NFA A161

NFA A174

NFA A180

NFA A180

NFA A206

NFA A206

NFA A213

NFA A213

NFA A230

NFA A230

NFA A241

NFA A249

NFA A257

NFA A265

NFA A272

NFA A425

NFA A430

NFA 1069 (SA 8005)

I40

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