US Bridges

US 78 over Great Cypress Swamp #2

Fair

Dorchester County, South Carolina · 6.8 MI NW of Sumrvl · Structure no. 000000000000275

Built
1928
97 years old, rebuilt 1934
Condition
Fair
inspected April 2024
Type
Culvert
Concrete
Length
25 ft
2 main spans
Daily traffic
7,800
2023 count
Owner
State
State Highway Agency

About this bridge

US 78 over Great Cypress Swamp #2 is a concrete culvert carrying US 78 over Great Cypress Swamp #2 in Dorchester County, South Carolina. It was built in 1928 and reconstructed in 1934, so it is 97 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 7,800 vehicles a day, roughly 10% of them trucks, projected to reach 11,154 by 2043. The structure is 25 ft (7.7 m) long and 34 ft wide. If it were closed, the detour would be 23 mi (37 km).

Location

Open in Google Maps
CarriesUS 78
CrossesGreat Cypress Swamp #2
Location6.8 MI NW of Sumrvl
RouteU.S. Route 78
CountyDorchester County
StateSouth Carolina
Coordinates33.08917, -80.26592
Functional classRural Principal Arterial - Other

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 inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating50.7 US tons
Inventory rating30.3 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckConcrete, cast-in-place
Main spans2
Design loadUnknown
Structure length25 ft (7.7 m)
Longest span12 ft (3.7 m)
Deck width34 ft (10.5 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,800 (2023)
Projected traffic11,154 by 2043
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed23 mi (37 km)
TollOn a free road
National Highway SystemYes

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$75,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was US 78 over Great Cypress Swamp #2 built?

It was built in 1928, making it 97 years old in 2025. It was reconstructed in 1934.

What condition is US 78 over Great Cypress Swamp #2 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 April 2024.

How much traffic does US 78 over Great Cypress Swamp #2 carry?

About 7,800 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is US 78 over Great Cypress Swamp #2?

The structure is 25 ft (7.7 m) long with a longest span of 12 ft (3.7 m) and a deck 34 ft wide.

Who owns US 78 over Great Cypress Swamp #2?

It is owned by the State Highway Agency.