US Bridges

C-4-29 over Rock CR

Fair

Anderson County, South Carolina · 8.9 MI NE of Anderson · Structure no. 000000000004451

Built
1965
60 years old
Condition
Fair
inspected October 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
25 ft
1 main span
Daily traffic
3,000
2023 count
Owner
County
County Highway Agency

About this bridge

C-4-29 over Rock CR is a steel stringer/multi-beam or girder carrying C-4-29 over Rock CR in Anderson County, South Carolina. It was built in 1965, so it is 60 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 3,000 vehicles a day, roughly 3% of them trucks, projected to reach 5,490 by 2043. The structure is 25 ft (7.6 m) long and 24 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesC-4-29
CrossesRock CR
Location8.9 MI NE of Anderson
RouteCounty Highway 29
CountyAnderson County
StateSouth Carolina
Coordinates34.57614, -82.51808
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating68.9 US tons
Inventory rating41.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length25 ft (7.6 m)
Longest span25 ft (7.6 m)
Deck width24 ft (7.2 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,000 (2023)
Projected traffic5,490 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedWidening with deck rehabilitation or replacement
Estimated improvement cost$131,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was C-4-29 over Rock CR built?

It was built in 1965, making it 60 years old in 2025.

What condition is C-4-29 over Rock CR 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 October 2023.

How much traffic does C-4-29 over Rock CR carry?

About 3,000 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is C-4-29 over Rock CR?

The structure is 25 ft (7.6 m) long with a longest span of 25 ft (7.6 m) and a deck 24 ft wide.

Who owns C-4-29 over Rock CR?

It is owned by the County Highway Agency.