US Bridges

S-10-317 over Drayton Swamp

Fair

Charleston County, South Carolina · 13.5 MI SW Sumrvl · Structure no. 000000000002146

Built
1955
70 years old
Condition
Fair
inspected June 2024
Type
Slab
Concrete
Length
70 ft
5 main spans
Daily traffic
125
2023 count
Owner
State
State Highway Agency

About this bridge

S-10-317 over Drayton Swamp is a concrete slab carrying S-10-317 over Drayton Swamp in Charleston County, South Carolina. It was built in 1955, so it is 70 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 125 vehicles a day, roughly 5% of them trucks, projected to reach 160 by 2043. The structure is 70 ft (21.3 m) long and 29 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesS-10-317
CrossesDrayton Swamp
Location13.5 MI SW Sumrvl
RouteState Highway 317
CountyCharleston County
StateSouth Carolina
Coordinates32.85192, -80.3018
Functional classRural Local

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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating31.1 US tons
Inventory rating18.5 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, precast panels
Main spans5
Design loadH 10
Structure length70 ft (21.3 m)
Longest span14 ft (4.3 m)
Deck width29 ft (8.8 m)
Roadway width28 ft (8.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic125 (2023)
Projected traffic160 by 2043
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 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-10-317 over Drayton Swamp built?

It was built in 1955, making it 70 years old in 2025.

What condition is S-10-317 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 June 2024.

How much traffic does S-10-317 over Drayton Swamp carry?

About 125 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is S-10-317 over Drayton Swamp?

The structure is 70 ft (21.3 m) long with a longest span of 14 ft (4.3 m) and a deck 29 ft wide.

Who owns S-10-317 over Drayton Swamp?

It is owned by the State Highway Agency.