US Bridges

US 15 over Mechanicsville Swamp

Fair

Lee County, South Carolina · 9 MI SW of Bishopville · Structure no. 000000000001736

Built
1930
95 years old, rebuilt 1961
Condition
Fair
inspected April 2024
Type
Culvert
Concrete
Length
32 ft
3 main spans
Daily traffic
4,500
2023 count
Owner
State
State Highway Agency

About this bridge

US 15 over Mechanicsville Swamp is a concrete culvert carrying US 15 over Mechanicsville Swamp in Lee County, South Carolina. It was built in 1930 and reconstructed in 1961, so it is 95 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 4,500 vehicles a day, roughly 11% of them trucks, projected to reach 7,155 by 2043. The structure is 32 ft (9.8 m) long and 51 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesUS 15
CrossesMechanicsville Swamp
Location9 MI SW of Bishopville
RouteU.S. Route 15
CountyLee County
StateSouth Carolina
Coordinates34.10116, -80.31459
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 protection8 Very GoodNo problems noted.
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 geometry6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating51 US tons
Inventory rating30.3 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans3
Design loadH 15
Structure length32 ft (9.8 m)
Longest span10 ft (3 m)
Deck width51 ft (15.5 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,500 (2023)
Projected traffic7,155 by 2043
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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 Mechanicsville Swamp built?

It was built in 1930, making it 95 years old in 2025. It was reconstructed in 1961.

What condition is US 15 over Mechanicsville 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 April 2024.

How much traffic does US 15 over Mechanicsville Swamp carry?

About 4,500 vehicles per day (2023 count), of which roughly 11% are trucks.

How long is US 15 over Mechanicsville Swamp?

The structure is 32 ft (9.8 m) long with a longest span of 10 ft (3 m) and a deck 51 ft wide.

Who owns US 15 over Mechanicsville Swamp?

It is owned by the State Highway Agency.