US Bridges

I-95 over Polk Swamp

Fair

Dorchester County, South Carolina · 2 MI W of ST George · Structure no. 000000000006475

Built
1974
51 years old
Condition
Fair
inspected July 2024
Type
Culvert
Concrete
Length
53 ft
5 main spans
Daily traffic
50,100
2023 count
Owner
State
State Highway Agency

About this bridge

I-95 over Polk Swamp is a concrete culvert carrying I-95 over Polk Swamp in Dorchester County, South Carolina. It was built in 1974, so it is 51 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 5 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 50,100 vehicles a day, roughly 19% of them trucks, projected to reach 87,675 by 2043. The structure is 53 ft (16.3 m) long. If it were closed, the detour would be 14.9 mi (24 km).

Location

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CarriesI-95
CrossesPolk Swamp
Location2 MI W of ST George
RouteInterstate 95
CountyDorchester County
StateSouth Carolina
Coordinates33.18628, -80.60943
Functional classRural Principal Arterial - Interstate

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 protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJuly 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
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating50 US tons
Inventory rating38.6 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans5
Design loadHS 20
Structure length53 ft (16.3 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50,100 (2023)
Projected traffic87,675 by 2043
Trucks19%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed14.9 mi (24 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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 I-95 over Polk Swamp built?

It was built in 1974, making it 51 years old in 2025.

What condition is I-95 over Polk 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 July 2024.

How much traffic does I-95 over Polk Swamp carry?

About 50,100 vehicles per day (2023 count), of which roughly 19% are trucks.

How long is I-95 over Polk Swamp?

The structure is 53 ft (16.3 m) long with a longest span of 10 ft (3 m).

Who owns I-95 over Polk Swamp?

It is owned by the State Highway Agency.