County profile · official public datasets

Lancaster County, SC

181 public highway bridges tracked in the FHWA National Bridge Inventory: 29.3% rated Good, 58% Fair, 12.7% Poor.

181
Public bridges: 29.3%
Good condition: 12.7%
Poor condition

The verdict

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

Lancaster 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.

43rd
of 46 on Poor share: 12.7%
Poor-condition share: 181
public highway bridges: 1967
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.

Lancaster County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Lancaster County ranks #43 of 46 South Carolina counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 12.7%). Lancaster County, South Carolina contains 181 public highway bridges. Roughly 29.3% are rated “Good,” 58% “Fair,” and 12.7% “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

181

Public highway bridges in Lancaster County

Good condition

29.3%

53 of 181 rated 7-9

Fair condition

58%

105 of 181 rated 5-6

Poor condition

12.7%

23 of 181 rated 4 or below

In-state Poor-share rank

#43 of 46

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

Condition distribution

Share of 181 NBI-tracked bridges by lowest applicable component rating.

Good

29.3% (53)

Fair

58% (105)

Poor

12.7% (23)

Lancaster County's Poor-condition bridges carry 55,350 vehicle crossings a day

That is 8.6% of the county's reported daily bridge traffic on 12.7% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 2,407 crossings a day against 3,331 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 181 of 181 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

64.6% of Lancaster County's bridges have passed the 50-year mark

117 of the 181 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 29.3% 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 18.5% of the county's Poor-condition bridge traffic

US 521 SB over RR CSXT, built 1929, carries 10,250 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 23-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 55,350 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1920s

28
1930s

14
1940s

12
1950s

11
1960s

33
1970s

26
1980s

16
1990s

12
2000s

13
2010s

13
2020s

3

What this shows Construction peaked in the 1960s, when 33 of the county's bridges still in the inventory were built, which is 18.2% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year is 1967, 10 years older than the South Carolina average of 1977.

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

The 5 South Carolina counties nearest Lancaster County in number of bridges, with their condition splits. Its 12.7% Poor share is the 6th-lowest of these 6. Its average build year of 1967 against a peer-group mean of 1976 is 9 years older.

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

Bridge inventory size and condition shares for Lancaster County and the 5 South Carolina counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Williamsburg County	195	38.5%	54.9%	6.7%	1977
Chester County	190	40.5%	50%	9.5%	1976
Lancaster County (this page)	181	29.3%	58%	12.7%	1967
Darlington County	174	32.8%	62.1%	5.2%	1974
Kershaw County	174	39.7%	55.2%	5.2%	1978
Clarendon County	170	25.3%	72.9%	1.8%	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 Lancaster 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 Lancaster County, both outside South Carolina so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside SC (181 bridges here).

Lamar County, AL · 181 bridges
Jasper County, IL · 181 bridges
Malheur County, OR · 181 bridges
Potter County, TX · 181 bridges

Similar average build year

Nearest mean year-built outside SC (1967 here).

Los Angeles County, CA · avg 1967 · 3,547 bridges
Allegheny County, PA · avg 1967 · 1,294 bridges
Sonoma County, CA · avg 1967 · 609 bridges
Merced County, CA · avg 1967 · 528 bridges

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

All 181 Good 53 Fair 105 Poor 23

Fair-condition bridges (105)

Sort:

Lancaster County Bridge Snapshot

Condition distribution

Lancaster County's Poor-condition bridges carry 55,350 vehicle crossings a day

64.6% of Lancaster County's bridges have passed the 50-year mark

One structure carries 18.5% of the county's Poor-condition bridge traffic

How Lancaster 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

Fair-condition bridges (105)

S-29-20

S-29-471

US 521

SC 75

S-29-39

SC 9 NB

US 521 SB

S-29-71

SC 9

US 521 NB

S-29-156

US 521

S-29-614

S-29-51

US 521 SB

S-29-50

S-29-156

US 521 NB

S-29-41

S-29-13

US 601

S-29-19

SC 200

S-29-72

S-29-51

S-29-99

SC 9

S-29-71

S-29-72

SC 9

US 521 NB

SC 97

S-29-154

C-29-1104

SC 903

S-29-28

US 601

SC 9 NB

US 521 SB

SC 9 SB

S-29-19

S-29-75

SC 97

S-29-71

US 521 NB

SC 9

US 521

SC 903

S-29-29

SC 9

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