US Bridges

Sc 403 over I-20

Fair

Darlington County, South Carolina · 2MI NE of Lamar · Structure no. 000000000006462

Built
1974
51 years old
Condition
Fair
inspected January 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
284 ft
4 main spans
Daily traffic
4,900
2023 count
Owner
State
State Highway Agency

About this bridge

Sc 403 over I-20 is a steel stringer/multi-beam or girder carrying Sc 403 over I-20 in Darlington County, South Carolina. It was built in 1974, so it is 51 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 4,900 vehicles a day, roughly 11% of them trucks, projected to reach 7,154 by 2043. The structure is 284 ft (86.6 m) long and 48 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesSc 403
CrossesI-20
Location2MI NE of Lamar
RouteState Highway 403
CountyDarlington County
StateSouth Carolina
Coordinates34.208, -80.04136
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.
Last inspectionJanuary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating57.1 US tons
Inventory rating44 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length284 ft (86.6 m)
Longest span101 ft (30.8 m)
Deck width48 ft (14.5 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,900 (2023)
Projected traffic7,154 by 2043
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Sc 403 over I-20 built?

It was built in 1974, making it 51 years old in 2025.

What condition is Sc 403 over I-20 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 January 2024.

How much traffic does Sc 403 over I-20 carry?

About 4,900 vehicles per day (2023 count), of which roughly 11% are trucks.

How long is Sc 403 over I-20?

The structure is 284 ft (86.6 m) long with a longest span of 101 ft (30.8 m) and a deck 48 ft wide.

Who owns Sc 403 over I-20?

It is owned by the State Highway Agency.