US Bridges

Sc 171/FOLLY RD over Long Island River

Good

Charleston County, South Carolina · 1 1/2 MI N of Folly Beach · Structure no. 000000000002301

Built
2016
9 years old
Condition
Good
inspected August 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
825 ft
11 main spans
Daily traffic
14,800
2023 count
Owner
State
State Highway Agency

About this bridge

Sc 171/FOLLY RD over Long Island River is a prestressed concrete continuous stringer/multi-beam or girder carrying Sc 171/FOLLY RD over Long Island River in Charleston County, South Carolina. It was built in 2016, so it is 9 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 14,800 vehicles a day, roughly 2% of them trucks, projected to reach 21,164 by 2043. The structure is 825 ft (251.5 m) long and 49 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

CarriesSc 171/FOLLY RD
CrossesLong Island River
Location1 1/2 MI N of Folly Beach
RouteState Highway 171
Coordinates32.67574, -79.95088
Functional classUrban Other Principal Arterial

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 protection8 Very GoodNo problems noted.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating53.6 US tons
Inventory rating41.4 US tons

Structure

MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans11
Design loadHL 93
Structure length825 ft (251.5 m)
Longest span75 ft (22.9 m)
Deck width49 ft (14.9 m)
Roadway width35 ft (10.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic14,800 (2023)
Projected traffic21,164 by 2043
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed123.7 mi (199 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 171/FOLLY RD over Long Island River built?

It was built in 2016, making it 9 years old in 2025.

What condition is Sc 171/FOLLY RD over Long Island 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 August 2024.

How much traffic does Sc 171/FOLLY RD over Long Island River carry?

About 14,800 vehicles per day (2023 count), of which roughly 2% are trucks.

How long is Sc 171/FOLLY RD over Long Island River?

The structure is 825 ft (251.5 m) long with a longest span of 75 ft (22.9 m) and a deck 49 ft wide.

Who owns Sc 171/FOLLY RD over Long Island River?

It is owned by the State Highway Agency.