US Bridges

S-18-377 over Unnamed Stream

Fair

Dorchester County, South Carolina · 1.7 MI SE Summerville · Structure no. 000000000004762

Built
1966
59 years old
Condition
Fair
inspected April 2023
Type
Slab
Concrete
Length
45 ft
3 main spans
Daily traffic
13,300
2023 count
Owner
State
State Highway Agency

About this bridge

S-18-377 over Unnamed Stream is a concrete slab carrying S-18-377 over Unnamed Stream in Dorchester County, South Carolina. It was built in 1966, so it is 59 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 13,300 vehicles a day, roughly 2% of them trucks, projected to reach 18,221 by 2043. The structure is 45 ft (13.7 m) long and 28 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesS-18-377
CrossesUnnamed Stream
Location1.7 MI SE Summerville
RouteState Highway 377
CountyDorchester County
StateSouth Carolina
Coordinates32.98813, -80.15942
Functional classUrban 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 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 geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46.1 US tons
Inventory rating27.4 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, precast panels
Main spans3
Design loadH 15
Structure length45 ft (13.7 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 traffic13,300 (2023)
Projected traffic18,221 by 2043
Trucks2%
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 statusNot eligible for the National Register of Historic Places
Work proposedWidening with deck rehabilitation or replacement
Estimated improvement cost$219,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was S-18-377 over Unnamed Stream built?

It was built in 1966, making it 59 years old in 2025.

What condition is S-18-377 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-18-377 over Unnamed Stream carry?

About 13,300 vehicles per day (2023 count), of which roughly 2% are trucks.

How long is S-18-377 over Unnamed Stream?

The structure is 45 ft (13.7 m) long with a longest span of 15 ft (4.6 m) and a deck 28 ft wide.

Who owns S-18-377 over Unnamed Stream?

It is owned by the State Highway Agency.