US Bridges

US 15 over Cowpen Swamp

Fair

Sumter County, South Carolina · 10 MI N of Sumter · Structure no. 000000000000751

Built
1936
89 years old, rebuilt 1965
Condition
Fair
inspected May 2024
Type
Culvert
Concrete Continuous
Length
21 ft
2 main spans
Daily traffic
4,000
2023 count
Owner
State
State Highway Agency

About this bridge

US 15 over Cowpen Swamp is a concrete continuous culvert carrying US 15 over Cowpen Swamp in Sumter County, South Carolina. It was built in 1936 and reconstructed in 1965, so it is 89 years old, older than the South Carolina average of 48 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 4,000 vehicles a day, roughly 12% of them trucks, projected to reach 6,360 by 2043. The structure is 21 ft (6.4 m) long and 46 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesUS 15
CrossesCowpen Swamp
Location10 MI N of Sumter
RouteU.S. Route 15
CountySumter County
StateSouth Carolina
Coordinates34.04236, -80.32131
Functional classRural Minor Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating38.3 US tons
Inventory rating22.8 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadH 15
Structure length21 ft (6.4 m)
Longest span10 ft (3 m)
Deck width46 ft (14 m)
Roadway width38 ft (11.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,000 (2023)
Projected traffic6,360 by 2043
Trucks12%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$58,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was US 15 over Cowpen Swamp built?

It was built in 1936, making it 89 years old in 2025. It was reconstructed in 1965.

What condition is US 15 over Cowpen Swamp in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in May 2024.

How much traffic does US 15 over Cowpen Swamp carry?

About 4,000 vehicles per day (2023 count), of which roughly 12% are trucks.

How long is US 15 over Cowpen Swamp?

The structure is 21 ft (6.4 m) long with a longest span of 10 ft (3 m) and a deck 46 ft wide.

Who owns US 15 over Cowpen Swamp?

It is owned by the State Highway Agency.