US Bridges

S-18-137 over Drayton Swamp

Fair

Dorchester County, South Carolina · 15.0 MI SW Summerville · Structure no. 000000000002512

Built
1957
68 years old, rebuilt 1996
Condition
Fair
inspected April 2023
Type
Slab
Concrete
Length
28 ft
2 main spans
Daily traffic
250
2023 count
Owner
State
State Highway Agency

About this bridge

S-18-137 over Drayton Swamp is a concrete slab carrying S-18-137 over Drayton Swamp in Dorchester County, South Carolina. It was built in 1957 and reconstructed in 1996, so it is 68 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 250 vehicles a day, roughly 23% of them trucks, projected to reach 348 by 2043. The structure is 28 ft (8.5 m) long and 26 ft wide. If it were closed, the detour would be 26.1 mi (42 km).

Location

Open in Google Maps
CarriesS-18-137
CrossesDrayton Swamp
Location15.0 MI SW Summerville
RouteState Highway 137
CountyDorchester County
StateSouth Carolina
Coordinates32.90095, -80.3853
Functional classRural Minor 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 protection8 Very GoodNo problems noted.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment8: Equal to present desirable criteria
Operating rating55 US tons
Inventory rating32.8 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, precast panels
Main spans2
Design loadH 15
Structure length28 ft (8.5 m)
Longest span14 ft (4.3 m)
Deck width26 ft (7.8 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic250 (2023)
Projected traffic348 by 2043
Trucks23%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed26.1 mi (42 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 S-18-137 over Drayton Swamp built?

It was built in 1957, making it 68 years old in 2025. It was reconstructed in 1996.

What condition is S-18-137 over Drayton 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 2023.

How much traffic does S-18-137 over Drayton Swamp carry?

About 250 vehicles per day (2023 count), of which roughly 23% are trucks.

How long is S-18-137 over Drayton Swamp?

The structure is 28 ft (8.5 m) long with a longest span of 14 ft (4.3 m) and a deck 26 ft wide.

Who owns S-18-137 over Drayton Swamp?

It is owned by the State Highway Agency.