US Bridges

Sc 9 Sbl over Mitchell Swamp

Good

Horry County, South Carolina · 1.0 MI SE of Green Sea · Structure no. 000000000007479

Built
1981
44 years old
Condition
Good
inspected August 2024
Type
Slab
Concrete
Length
150 ft
5 main spans
Daily traffic
4,700
2023 count
Owner
State
State Highway Agency

About this bridge

Sc 9 Sbl over Mitchell Swamp is a concrete slab carrying Sc 9 Sbl over Mitchell Swamp in Horry County, South Carolina. It was built in 1981, so it is 44 years old, younger than the South Carolina average of 48 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 4,700 vehicles a day, roughly 11% of them trucks, projected to reach 8,178 by 2043. The structure is 150 ft (45.7 m) long and 43 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesSc 9 Sbl
CrossesMitchell Swamp
Location1.0 MI SE of Green Sea
RouteState Highway 9
Coordinates34.11665, -78.96757
Functional classRural Principal Arterial - Other

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation7: Better than present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59.3 US tons
Inventory rating45.7 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length150 ft (45.7 m)
Longest span30 ft (9.1 m)
Deck width43 ft (13.1 m)
Roadway width39 ft (12 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,700 (2023)
Projected traffic8,178 by 2043
Trucks11%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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 Sc 9 Sbl over Mitchell Swamp built?

It was built in 1981, making it 44 years old in 2025.

What condition is Sc 9 Sbl over Mitchell Swamp in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in August 2024.

How much traffic does Sc 9 Sbl over Mitchell Swamp carry?

About 4,700 vehicles per day (2023 count), of which roughly 11% are trucks.

How long is Sc 9 Sbl over Mitchell Swamp?

The structure is 150 ft (45.7 m) long with a longest span of 30 ft (9.1 m) and a deck 43 ft wide.

Who owns Sc 9 Sbl over Mitchell Swamp?

It is owned by the State Highway Agency.