US Bridges

S-18-161 over Gum Branch

Fair

Dorchester County, South Carolina · 4.6 MI SE ST George · Structure no. 000000000006657

Built
1975
50 years old
Condition
Fair
inspected April 2023
Type
Slab
Concrete
Length
60 ft
4 main spans
Daily traffic
125
2023 count
Owner
State
State Highway Agency

About this bridge

S-18-161 over Gum Branch is a concrete slab carrying S-18-161 over Gum Branch in Dorchester County, South Carolina. It was built in 1975, so it is 50 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 60 ft (18.3 m) long and 33 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesS-18-161
CrossesGum Branch
Location4.6 MI SE ST George
RouteState Highway 161
CountyDorchester County
StateSouth Carolina
Coordinates33.13219, -80.52197
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 protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 geometry6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating48.6 US tons
Inventory rating28.9 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, precast panels
Main spans4
Design loadH 15
Structure length60 ft (18.3 m)
Longest span15 ft (4.6 m)
Deck width33 ft (10.1 m)
Roadway width31 ft (9.6 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 closed3.7 mi (6 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-18-161 over Gum Branch built?

It was built in 1975, making it 50 years old in 2025.

What condition is S-18-161 over Gum Branch 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-18-161 over Gum Branch carry?

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

How long is S-18-161 over Gum Branch?

The structure is 60 ft (18.3 m) long with a longest span of 15 ft (4.6 m) and a deck 33 ft wide.

Who owns S-18-161 over Gum Branch?

It is owned by the State Highway Agency.