US Bridges

S-21-711 over Bay Branch

Fair

Florence County, South Carolina · 3 MI W Timmonsville · Structure no. 000000000004118

Built
1963
62 years old, rebuilt 1999
Condition
Fair
inspected April 2023
Type
Slab
Concrete
Length
45 ft
3 main spans
Daily traffic
425
2023 count
Owner
State
State Highway Agency

About this bridge

S-21-711 over Bay Branch is a concrete slab carrying S-21-711 over Bay Branch in Florence County, South Carolina. It was built in 1963 and reconstructed in 1999, so it is 62 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 425 vehicles a day, roughly 8% of them trucks, projected to reach 157 by 2043. The structure is 45 ft (13.7 m) long and 28 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesS-21-711
CrossesBay Branch
Location3 MI W Timmonsville
RouteState Highway 711
CountyFlorence County
StateSouth Carolina
Coordinates34.13013, -79.99801
Functional classRural Minor 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
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 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 adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating30 US tons
Inventory rating17.9 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, precast panels
Main spans3
Design loadH 10
Structure length45 ft (13.7 m)
Longest span15 ft (4.6 m)
Deck width28 ft (8.6 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic425 (2023)
Projected traffic157 by 2043
Trucks8%
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-21-711 over Bay Branch built?

It was built in 1963, making it 62 years old in 2025. It was reconstructed in 1999.

What condition is S-21-711 over Bay 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-21-711 over Bay Branch carry?

About 425 vehicles per day (2023 count), of which roughly 8% are trucks.

How long is S-21-711 over Bay Branch?

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-21-711 over Bay Branch?

It is owned by the State Highway Agency.