County profile · official public datasets

Clarendon County, SC

170 public highway bridges tracked in the FHWA National Bridge Inventory: 25.3% rated Good, 72.9% Fair, 1.8% Poor.

170
Public bridges: 25.3%
Good condition: 1.8%
Poor condition

The verdict

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

Clarendon County posts a top-10% lowest Poor-condition share among rated counties in the state across mid-size county bridge inventory.

Top 9%
lowest Poor share in state: 1.8%
Poor-condition share: 170
public highway bridges: 1976
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.

Clarendon County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Clarendon County ranks #4 of 46 South Carolina counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 1.8%). Clarendon County, South Carolina contains 170 public highway bridges. Roughly 25.3% are rated “Good,” 72.9% “Fair,” and 1.8% “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

170

Public highway bridges in Clarendon County

Good condition

25.3%

43 of 170 rated 7-9

Fair condition

72.9%

124 of 170 rated 5-6

Poor condition

1.8%

3 of 170 rated 4 or below

In-state Poor-share rank

#4 of 46

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

Condition distribution

Share of 170 NBI-tracked bridges by lowest applicable component rating.

Good

25.3% (43)

Fair

72.9% (124)

Poor

1.8% (3)

Clarendon County's Poor-condition bridges carry 1,450 vehicle crossings a day

That is 0.2% of the county's reported daily bridge traffic on 1.8% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 483 crossings a day against 2,051 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 170 of 170 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

55.3% of Clarendon County's bridges have passed the 50-year mark

94 of the 170 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 25.3% 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 44.8% of the county's Poor-condition bridge traffic

S-14-56 over TAWCAW CREEK, built 1956, carries 650 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 3-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 1,450 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1920s

1
1930s

12
1940s

10
1950s

9
1960s

57
1970s

16
1980s

13
1990s

21
2000s

17
2010s

11
2020s

3

What this shows Construction peaked in the 1960s, when 57 of the county's bridges still in the inventory were built, which is 33.5% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1976) matches the South Carolina average (1977).

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

The 5 South Carolina counties nearest Clarendon County in number of bridges, with their condition splits. Its 1.8% Poor share is the 1st-lowest of these 6. Its average build year of 1976 against a peer-group mean of 1975 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 Clarendon County and the 5 South Carolina counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Lancaster County	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 (this page)	170	25.3%	72.9%	1.8%	1976
Sumter County	166	44%	45.2%	10.8%	1981
Abbeville County	163	41.1%	55.8%	3.1%	1975

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 Clarendon 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 Clarendon County, both outside South Carolina so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside SC (170 bridges here).

Rush County, KS · 170 bridges
Itasca County, MN · 170 bridges
Montgomery County, MS · 170 bridges
Brown County, SD · 170 bridges

Similar average build year

Nearest mean year-built outside SC (1976 here).

Marion County, IN · avg 1976 · 958 bridges
Mohave County, AZ · avg 1976 · 641 bridges
Comanche County, OK · avg 1976 · 593 bridges
Prince George's County, MD · avg 1976 · 576 bridges

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

All 170 Good 43 Fair 124 Poor 3

All bridges (170)

Sort:

I-95 NB

Fair

Over: BLACK SWAMP (NO. 3)

14MI N OF MANNING, Clarendon, SC

Built 1968 Load: 43.4 t ADT: 16,900

I-95

Fair

Over: BLACK SWAMP (NO. 4)

15MI N OF MANNING, Clarendon, SC

Built 1968 Load: 43.4 t ADT: 16,900

I-95 NB

Fair

Over: BLACK SWAMP (NO. 5)

15MI N OF MANNING, Clarendon, SC

Built 1968 Load: 43.4 t ADT: 16,900

I-95 SB

Fair

Over: BLACK SWAMP (NO. 1)

14MI N OF MANNING, Clarendon, SC

Built 1968 Load: 43.7 t ADT: 16,900

I-95 SB

Fair

Over: BLACK RIVER (NO. 2)

14MI N OF MANNING, Clarendon, SC

Built 1968 Load: 43.7 t ADT: 16,900

I-95 SB

Fair

Over: BLACK SWAMP (NO. 3)

14MI N OF MANNING, Clarendon, SC

Built 1968 Load: 43.7 t ADT: 16,900

I-95 SB

Fair

Over: BLACK SWAMP (NO. 4)

15MI NE OF MANNING, Clarendon, SC

Built 1968 Load: 43.7 t ADT: 16,900

I-95 SB

Fair

Over: BLACK SWAMP (NO. 5)

15MI NE OF MANNING, Clarendon, SC

Built 1968 Load: 43.7 t ADT: 16,900

S-14-36

Fair

Over: TRIB TO PUDDING SWAMP

2.5MI S TURBEVILLE, Clarendon, SC

Built 1999 Load: 43.7 t ADT: 1,150

I-95 NB

Fair

Over: US 15

7MI SW OF SUMMERTON, Clarendon, SC

Built 1968 Load: 45.0 t ADT: 20,050

I-95 SB

Fair

Over: US 15

7MI SW OF SUMMERTON, Clarendon, SC

Built 1968 Load: 45.0 t ADT: 20,050

S-14-25

Fair

Over: TAWCAW CREEK

1MI SE SUMMERTON, Clarendon, SC

Built 1949 Load: 45.4 t ADT: 1,000

I-95 NB

Fair

Over: US 521-301 CON/SCL RR

3MI N OF MANNING, Clarendon, SC

Built 1968 Load: 45.4 t ADT: 18,600

I-95 SB

Fair

Over: US 521-301 CON/SCL RR

3MI N OF MANNING, Clarendon, SC

Built 1968 Load: 45.4 t ADT: 18,600

US 378

Fair

Over: DOUGLAS SWAMP

3MI E OF TURBEVILLE, Clarendon, SC

Built 2007 Load: 46.0 t ADT: 5,500

I-95 NB

Fair

Over: LAKE MARION RELIEF

7MI S OF SUMMERTON, Clarendon, SC

Built 1968 Load: 46.3 t ADT: 20,050

I-95 SB

Fair

Over: LAKE MARION RELIEF

7MI S OF SUMMERTON, Clarendon, SC

Built 1968 Load: 46.3 t ADT: 20,050

SC 261

Fair

Over: S.C.L. RAILROAD

3MI E OF MANNING, Clarendon, SC

Built 1969 Load: 47.3 t ADT: 1,950

SC 261

Fair

Over: I-95

2MI W OF MANNING, Clarendon, SC

Built 1969 Load: 48.3 t ADT: 4,600

S-14-51

Fair

Over: HOYE BRANCH

7MI NW MANNING, Clarendon, SC

Built 1987 Load: 48.6 t ADT: 275

I-95

Fair

Over: TAWCAW CREEK

2MI NE OF SUMMERTON, Clarendon, SC

Built 1967 Load: 53.5 t ADT: 36,000

US 301

Fair

Over: POCOTALIGO SWAMP (NO. 6)

0.5MI N OF MANNING, Clarendon, SC

Built 2006 Load: 54.8 t ADT: 9,400

US 301

Fair

Over: POCOTALIGO SWAMP (NO. 7)

0.5MI N OF MANNING, Clarendon, SC

Built 2006 Load: 54.8 t ADT: 9,400

US 301

Fair

Over: POCOTALIGO RIVER (NO. 8)

1.3 MI N MANNING, Clarendon, SC

Clarendon County Bridge Snapshot

Condition distribution

Clarendon County's Poor-condition bridges carry 1,450 vehicle crossings a day

55.3% of Clarendon County's bridges have passed the 50-year mark

One structure carries 44.8% of the county's Poor-condition bridge traffic

How Clarendon 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

All bridges (170)

I-95 NB

I-95

I-95 NB

I-95 SB

I-95 SB

I-95 SB

I-95 SB

I-95 SB

S-14-36

I-95 NB

I-95 SB

S-14-25

I-95 NB

I-95 SB

US 378

I-95 NB

I-95 SB

SC 261

SC 261

S-14-51

I-95

US 301

US 301

US 301

S-14-23

S-14-37

S-14-40

S-14-40

S-14-104

S-14-262

S-14-49

S-14-45

S-14-61

SC 260

S-14-76

S-14-26

S-14-213

S-14-48

US 378 EB

US 301

S-14-125

S-14-123

S-14-23

S-14-35

S-14-211

S-14-19

S-14-50

S-14-36

S-14-50

S-14-345

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