US Bridges

S-18-56 over Unnamed Stream

Fair

Dorchester County, South Carolina · 3.2 MI SW Ridgeville · Structure no. 000000000004309

Built
1964
61 years old
Condition
Fair
inspected April 2023
Type
Slab
Concrete
Length
30 ft
2 main spans
Daily traffic
375
2023 count
Owner
State
State Highway Agency

About this bridge

S-18-56 over Unnamed Stream is a concrete slab carrying S-18-56 over Unnamed Stream in Dorchester County, South Carolina. It was built in 1964, so it is 61 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 375 vehicles a day, roughly 9% of them trucks, projected to reach 514 by 2043. The structure is 30 ft (9.1 m) long and 28 ft wide. If it were closed, the detour would be 8.7 mi (14 km).

Location

Open in Google Maps
CarriesS-18-56
CrossesUnnamed Stream
Location3.2 MI SW Ridgeville
RouteState Highway 56
CountyDorchester County
StateSouth Carolina
Coordinates33.08474, -80.37352
Functional classRural Major 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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
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 adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating47.5 US tons
Inventory rating28.2 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, precast panels
Main spans2
Design loadH 15
Structure length30 ft (9.1 m)
Longest span15 ft (4.6 m)
Deck width28 ft (8.4 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic375 (2023)
Projected traffic514 by 2043
Trucks9%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.7 mi (14 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-18-56 over Unnamed Stream built?

It was built in 1964, making it 61 years old in 2025.

What condition is S-18-56 over Unnamed Stream 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-18-56 over Unnamed Stream carry?

About 375 vehicles per day (2023 count), of which roughly 9% are trucks.

How long is S-18-56 over Unnamed Stream?

The structure is 30 ft (9.1 m) long with a longest span of 15 ft (4.6 m) and a deck 28 ft wide.

Who owns S-18-56 over Unnamed Stream?

It is owned by the State Highway Agency.