US Bridges

Sc 517 over Intracoastal Waterway

Fair

Charleston County, South Carolina · 10.1 MI NE of Charleston · Structure no. 000000000008720

Built
1993
32 years old
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
11,461 ft
101 main spans
Daily traffic
20,000
2023 count
Owner
State
State Highway Agency

About this bridge

Sc 517 over Intracoastal Waterway is a prestressed concrete continuous stringer/multi-beam or girder carrying Sc 517 over Intracoastal Waterway in Charleston County, South Carolina. It was built in 1993, so it is 32 years old, younger 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 20,000 vehicles a day, roughly 3% of them trucks, projected to reach 28,600 by 2043. The structure is 11,461 ft (3,493.3 m) long and 57 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesSc 517
CrossesIntracoastal Waterway
Location10.1 MI NE of Charleston
RouteState Highway 517
CountyCharleston County
StateSouth Carolina
Coordinates32.80305, -79.79772
Functional classUrban Other Principal Arterial

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 inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating80 US tons
Inventory rating44 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans101
Design loadHS 20 + Mod
Structure length11,461 ft (3,493.3 m)
Longest span135 ft (41.1 m)
Deck width57 ft (17.4 m)
Roadway width54 ft (16.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic20,000 (2023)
Projected traffic28,600 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemYes

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—
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was Sc 517 over Intracoastal Waterway built?

It was built in 1993, making it 32 years old in 2025.

What condition is Sc 517 over Intracoastal Waterway 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 2024.

How much traffic does Sc 517 over Intracoastal Waterway carry?

About 20,000 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Sc 517 over Intracoastal Waterway?

The structure is 11,461 ft (3,493.3 m) long with a longest span of 135 ft (41.1 m) and a deck 57 ft wide.

Who owns Sc 517 over Intracoastal Waterway?

It is owned by the State Highway Agency.