US Bridges

US 321 over Cypress Swamp

Fair

Jasper County, South Carolina · 7.0MI NW of Tillman · Structure no. 000000000001514

Built
1948
77 years old
Condition
Fair
inspected November 2023
Type
Tee Beam
Concrete
Length
81 ft
3 main spans
Daily traffic
4,100
2023 count
Owner
State
State Highway Agency

About this bridge

US 321 over Cypress Swamp is a concrete tee beam carrying US 321 over Cypress Swamp in Jasper County, South Carolina. It was built in 1948, so it is 77 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 4,100 vehicles a day, roughly 20% of them trucks, projected to reach 7,134 by 2043. The structure is 81 ft (24.7 m) long and 33 ft wide. If it were closed, the detour would be 11.2 mi (18 km).

Location

Open in Google Maps
CarriesUS 321
CrossesCypress Swamp
Location7.0MI NW of Tillman
RouteU.S. Route 321
CountyJasper County
StateSouth Carolina
Coordinates32.55222, -81.16778
Functional classRural Principal Arterial - Other

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionNovember 2023
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 geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating43.2 US tons
Inventory rating33.2 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 15
Structure length81 ft (24.7 m)
Longest span27 ft (8.2 m)
Deck width33 ft (10.1 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,100 (2023)
Projected traffic7,134 by 2043
Trucks20%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.2 mi (18 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 proposedWidening with deck rehabilitation or replacement
Estimated improvement cost$264,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was US 321 over Cypress Swamp built?

It was built in 1948, making it 77 years old in 2025.

What condition is US 321 over Cypress Swamp 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 2023.

How much traffic does US 321 over Cypress Swamp carry?

About 4,100 vehicles per day (2023 count), of which roughly 20% are trucks.

How long is US 321 over Cypress Swamp?

The structure is 81 ft (24.7 m) long with a longest span of 27 ft (8.2 m) and a deck 33 ft wide.

Who owns US 321 over Cypress Swamp?

It is owned by the State Highway Agency.