US Bridges

US 301 over Douglas Swamp

Fair

Florence County, South Carolina · 1MI SW of Olanta · Structure no. 000000000001876

Built
1924
101 years old, rebuilt 1952
Condition
Fair
inspected March 2024
Type
Tee Beam
Concrete
Length
88 ft
4 main spans
Daily traffic
2,000
2023 count
Owner
State
State Highway Agency

About this bridge

US 301 over Douglas Swamp is a concrete tee beam carrying US 301 over Douglas Swamp in Florence County, South Carolina. It was built in 1924 and reconstructed in 1952, so it is 101 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 2,000 vehicles a day, roughly 10% of them trucks, projected to reach 2,920 by 2043. The structure is 88 ft (26.8 m) long and 31 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesUS 301
CrossesDouglas Swamp
Location1MI SW of Olanta
RouteU.S. Route 301
CountyFlorence County
StateSouth Carolina
Coordinates33.932, -79.94728
Functional classRural Major Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 2024
Inspection intervalevery 12 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating30 US tons
Inventory rating17.9 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans4
Design loadH 15
Structure length88 ft (26.8 m)
Longest span22 ft (6.7 m)
Deck width31 ft (9.6 m)
Roadway width29 ft (8.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,000 (2023)
Projected traffic2,920 by 2043
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was US 301 over Douglas Swamp built?

It was built in 1924, making it 101 years old in 2025. It was reconstructed in 1952.

What condition is US 301 over Douglas 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 March 2024.

How much traffic does US 301 over Douglas Swamp carry?

About 2,000 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is US 301 over Douglas Swamp?

The structure is 88 ft (26.8 m) long with a longest span of 22 ft (6.7 m) and a deck 31 ft wide.

Who owns US 301 over Douglas Swamp?

It is owned by the State Highway Agency.