US Bridges

S-18-29 over Edisto River

Good

Dorchester County, South Carolina · 9 MI SE ST George · Structure no. 000000000007349

Built
1980
45 years old
Condition
Good
inspected May 2023
Type
Slab
Concrete
Length
240 ft
8 main spans
Daily traffic
750
2023 count
Owner
State
State Highway Agency

About this bridge

S-18-29 over Edisto River is a concrete slab carrying S-18-29 over Edisto River in Dorchester County, South Carolina. It was built in 1980, so it is 45 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 750 vehicles a day, roughly 16% of them trucks, projected to reach 1,095 by 2043. The structure is 240 ft (73.2 m) long and 35 ft wide.

CarriesS-18-29
CrossesEdisto River
Location9 MI SE ST George
RouteState Highway 29
Coordinates33.06172, -80.52433
Functional classRural Major Collector

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 protection7 GoodSome minor problems.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46.7 US tons
Inventory rating27.9 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans8
Design loadHS 15
Structure length240 ft (73.2 m)
Longest span30 ft (9.1 m)
Deck width35 ft (10.8 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic750 (2023)
Projected traffic1,095 by 2043
Trucks16%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed—
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-18-29 over Edisto River built?

It was built in 1980, making it 45 years old in 2025.

What condition is S-18-29 over Edisto River 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 May 2023.

How much traffic does S-18-29 over Edisto River carry?

About 750 vehicles per day (2023 count), of which roughly 16% are trucks.

How long is S-18-29 over Edisto River?

The structure is 240 ft (73.2 m) long with a longest span of 30 ft (9.1 m) and a deck 35 ft wide.

Who owns S-18-29 over Edisto River?

It is owned by the State Highway Agency.