County profile · official public datasets

Aiken County, SC

198 public highway bridges tracked in the FHWA National Bridge Inventory: 36.9% rated Good, 53.5% Fair, 9.6% Poor.

198
Public bridges: 36.9%
Good condition: 9.6%
Poor condition

The verdict

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

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

38th
of 46 on Poor share: 9.6%
Poor-condition share: 198
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.

Aiken County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Aiken County ranks #38 of 46 South Carolina counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 9.6%). Aiken County, South Carolina contains 198 public highway bridges. Roughly 36.9% are rated “Good,” 53.5% “Fair,” and 9.6% “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

198

Public highway bridges in Aiken County

Good condition

36.9%

73 of 198 rated 7-9

Fair condition

53.5%

106 of 198 rated 5-6

Poor condition

9.6%

19 of 198 rated 4 or below

In-state Poor-share rank

#38 of 46

Among South Carolina counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 198 NBI-tracked bridges by lowest applicable component rating.

Good

36.9% (73)

Fair

53.5% (106)

Poor

9.6% (19)

Aiken County's Poor-condition bridges carry 122,550 vehicle crossings a day

That is 8.1% of the county's reported daily bridge traffic on 9.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 6,450 crossings a day against 5,665 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 198 of 198 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

53% of Aiken County's bridges have passed the 50-year mark

105 of the 198 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 36.9% 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 15% of the county's Poor-condition bridge traffic

I-20 WB over S.C. 19, built 1968, carries 18,350 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 19-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 122,550 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1920s

5
1930s

8
1940s

6
1950s

28
1960s

42
1970s

22
1980s

14
1990s

21
2000s

37
2010s

11
2020s

4

What this shows Construction peaked in the 1960s, when 42 of the county's bridges still in the inventory were built, which is 21.2% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1977) matches the South Carolina average (1977).

How Aiken County compares with South Carolina's closest counties by inventory size

The 5 South Carolina counties nearest Aiken County in number of bridges, with their condition splits. Its 9.6% Poor share is the 5th-lowest of these 6. Its average build year of 1977 against a peer-group mean of 1976 is in line with the group.

Showing the 5 closest of 45 South Carolina counties eligible for comparison.

Bridge inventory size and condition shares for Aiken County and the 5 South Carolina counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Cherokee County	199	45.2%	43.7%	11.1%	1983
Chesterfield County	199	40.2%	54.8%	5%	1974
Dorchester County	198	28.8%	69.2%	2%	1972
Aiken County (this page)	198	36.9%	53.5%	9.6%	1977
Williamsburg County	195	38.5%	54.9%	6.7%	1977
Chester County	190	40.5%	50%	9.5%	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 Aiken 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 Aiken County, both outside South Carolina so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside SC (198 bridges here).

Scott County, AR · 198 bridges
Fulton County, OH · 198 bridges
Madison County, OH · 198 bridges
Erath County, TX · 198 bridges

Similar average build year

Nearest mean year-built outside SC (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
Shelby County, TN · avg 1977 · 1,077 bridges

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

All 198 Good 73 Fair 106 Poor 19

Good-condition bridges (73)

Sort:

Aiken County Bridge Snapshot

Condition distribution

Aiken County's Poor-condition bridges carry 122,550 vehicle crossings a day

53% of Aiken County's bridges have passed the 50-year mark

One structure carries 15% of the county's Poor-condition bridge traffic

How Aiken County compares with South Carolina'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 (73)

I-520 WB

I-20

S-2-33

US 278

S-2-49

S-2-779

S-2-53

S-33

US 25

S-2-1304

S-2-49

SC 302

SC 191

S-2-254

C-2-992

S-2-25

I-520 RAMPTOI-20W

I-520 EB

I-520 WB

I-520 WB

S-2-31 NBL

S-2-31 SBL

I-520 EB

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