County profile · official public datasets

Richland County, SC

361 public highway bridges tracked in the FHWA National Bridge Inventory: 50.1% rated Good, 46% Fair, 3.9% Poor.

361
Public bridges: 50.1%
Good condition: 3.9%
Poor condition

The verdict

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

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

Top 30%
lowest Poor share in state: 3.9%
Poor-condition share: 361
public highway bridges: 1979
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.

Richland County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Richland County ranks #14 of 46 South Carolina counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 3.9%). Richland County, South Carolina contains 361 public highway bridges. Roughly 50.1% are rated “Good,” 46% “Fair,” and 3.9% “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

361

Public highway bridges in Richland County

Good condition

50.1%

181 of 361 rated 7-9

Fair condition

46%

166 of 361 rated 5-6

Poor condition

3.9%

14 of 361 rated 4 or below

In-state Poor-share rank

#14 of 46

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

Condition distribution

Share of 361 NBI-tracked bridges by lowest applicable component rating.

Good

50.1% (181)

Fair

46% (166)

Poor

3.9% (14)

Richland County's Poor-condition bridges carry 110,270 vehicle crossings a day

That is 2% of the county's reported daily bridge traffic on 3.9% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 7,876 crossings a day against 14,719 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 361 of 361 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

39.6% of Richland County's bridges have passed the 50-year mark

143 of the 361 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 50.1% 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 33% of the county's Poor-condition bridge traffic

I-77 SB over US 21, built 1976, carries 36,350 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 14-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 110,270 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

1
1910s

5
1920s

11
1930s

13
1940s

19
1950s

17
1960s

48
1970s

58
1980s

72
1990s

52
2000s

19
2010s

33
2020s

13

What this shows Construction peaked in the 1980s, when 72 of the county's bridges still in the inventory were built, which is 19.9% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1979) matches the South Carolina average (1977).

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

The 5 South Carolina counties nearest Richland County in number of bridges, with their condition splits. Its 3.9% Poor share is the 3rd-lowest of these 6. Its average build year of 1979 against a peer-group mean of 1979 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 Richland County and the 5 South Carolina counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Richland County (this page)	361	50.1%	46%	3.9%	1979
Charleston County	336	37.8%	59.8%	2.4%	1988
Pickens County	291	48.1%	42.6%	9.3%	1979
York County	288	42.7%	49.7%	7.6%	1984
Florence County	277	33.9%	63.5%	2.5%	1976
Orangeburg County	273	17.9%	76.6%	5.5%	1966

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

Similar inventory size

Nearest county inventories outside SC (361 bridges here).

San Mateo County, CA · 361 bridges
Washita County, OK · 361 bridges
Gibson County, IN · 362 bridges
Fayette County, IA · 362 bridges

Similar average build year

Nearest mean year-built outside SC (1979 here).

Pima County, AZ · avg 1979 · 1,150 bridges
Jefferson County, KY · avg 1979 · 662 bridges
McPherson County, KS · avg 1979 · 586 bridges
Madison County, IL · avg 1979 · 523 bridges

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

All 361 Good 181 Fair 166 Poor 14

Good-condition bridges (181)

Sort:

Richland County Bridge Snapshot

Condition distribution

Richland County's Poor-condition bridges carry 110,270 vehicle crossings a day

39.6% of Richland County's bridges have passed the 50-year mark

One structure carries 33% of the county's Poor-condition bridge traffic

How Richland 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 (181)

SEMMES ROAD

RAMP OFF I-20 WB

S-40-54

S-40-33

BOYDEN ARBOR RD.

COLONELS CREEK RD.

SC 555 NB

S-40-827

US 176

SC 277 NB

I-77 SB

SC 555

SC 215

S-40-52 EB

S-40-52 WB

S-40-61

RAMP ON I-26 EB

S-40-129

SC 277 SB

SC 555 SB

S-40-907

L-40-3476

I-77 SB

I-77 NB

US 601

I-20

S-40-1196

S-40-434

RAMP ON I-77 NB

RAMP OFF I-77 SB

S-40-61

S-40-1571

I-77 SB

S-40-82

S-40-55

SC 12

SC 48 WB

S-40-1058

RAMP OFF I-20 WB

I-77 SB

I-77 NB

I-77 SB

S-40-1352

I-20 EB

I-77 NB

L-40-170

L-40-949

S-40-1274

S-40-1335

S-40-1721

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