US Bridges

US 15 over Four Hole Swamp

Good

Orangeburg County, South Carolina · 3.5 MI SW of Holly Hill · Structure no. 000000000001281

Built
2006
19 years old
Condition
Good
inspected December 2023
Type
Slab
Concrete Continuous
Length
180 ft
6 main spans
Daily traffic
850
2023 count
Owner
State
State Highway Agency

About this bridge

US 15 over Four Hole Swamp is a concrete continuous slab carrying US 15 over Four Hole Swamp in Orangeburg County, South Carolina. It was built in 2006, so it is 19 years old, younger than the South Carolina average of 48 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 850 vehicles a day, roughly 11% of them trucks, projected to reach 1,241 by 2043. The structure is 180 ft (54.9 m) long and 47 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

CarriesUS 15
CrossesFour Hole Swamp
Location3.5 MI SW of Holly Hill
RouteU.S. Route 15
Coordinates33.30571, -80.48373
Functional classRural Major Collector

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionDecember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating56.8 US tons
Inventory rating44 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans6
Design loadHS 25 or greater
Structure length180 ft (54.9 m)
Longest span30 ft (9.1 m)
Deck width47 ft (14.4 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic850 (2023)
Projected traffic1,241 by 2043
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
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 statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was US 15 over Four Hole Swamp built?

It was built in 2006, making it 19 years old in 2025.

What condition is US 15 over Four Hole Swamp in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in December 2023.

How much traffic does US 15 over Four Hole Swamp carry?

About 850 vehicles per day (2023 count), of which roughly 11% are trucks.

How long is US 15 over Four Hole Swamp?

The structure is 180 ft (54.9 m) long with a longest span of 30 ft (9.1 m) and a deck 47 ft wide.

Who owns US 15 over Four Hole Swamp?

It is owned by the State Highway Agency.