US Bridges

US 21 Bus over Beaufort River

FairPosted for load

Beaufort County, South Carolina · In Town of Beaufort · Structure no. 000000000003186

Built
1960
65 years old
Condition
Fair
inspected November 2024
Type
Movable - Swing
Steel
Length
2,290 ft
1 main span
Daily traffic
15,600
2023 count
Owner
State
State Highway Agency

About this bridge

US 21 Bus over Beaufort River is a steel movable - swing carrying US 21 Bus over Beaufort River in Beaufort County, South Carolina. It was built in 1960, so it is 65 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 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. Its operating status is: posted for other load-capacity restriction.

It carries about 15,600 vehicles a day, roughly 4% of them trucks, projected to reach 17,472 by 2043. The structure is 2,290 ft (698 m) long and 33 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesUS 21 Bus
CrossesBeaufort River
LocationIn Town of Beaufort
RouteU.S. Route 21
CountyBeaufort County
StateSouth Carolina
Coordinates32.42772, -80.66923
Functional classUrban Minor 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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusPosted for other load-capacity restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating38.6 US tons
Inventory rating23.3 US tons

Structure

Structure typeMovable - Swing
MaterialSteel
DeckConcrete, cast-in-place
Main spans1 (+36 approach)
Design loadHS 15
Structure length2,290 ft (698 m)
Longest span248 ft (75.5 m)
Deck width33 ft (10.1 m)
Roadway width25 ft (7.5 m)
Vertical clearance over deck15 ft (4.6 m)

Traffic and service

Average daily traffic15,600 (2023)
Projected traffic17,472 by 2043
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusListed on the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$13.2 million (2024 estimate)
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was US 21 Bus over Beaufort River built?

It was built in 1960, making it 65 years old in 2025.

What condition is US 21 Bus over Beaufort River 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 November 2024.

How much traffic does US 21 Bus over Beaufort River carry?

About 15,600 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is US 21 Bus over Beaufort River?

The structure is 2,290 ft (698 m) long with a longest span of 248 ft (75.5 m) and a deck 33 ft wide.

Who owns US 21 Bus over Beaufort River?

It is owned by the State Highway Agency.