US Bridges

I-26 EB over S-46/HERIOT ST

Fair

Charleston County, South Carolina · In Charleston · Structure no. 000000000005231

Built
1968
57 years old, rebuilt 2005
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
6,184 ft
76 main spans
Daily traffic
60,100
2023 count
Owner
State
State Highway Agency

About this bridge

I-26 EB over S-46/HERIOT ST is a steel stringer/multi-beam or girder carrying I-26 EB over S-46/HERIOT ST in Charleston County, South Carolina. It was built in 1968 and reconstructed in 2005, so it is 57 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.

It carries about 60,100 vehicles a day, roughly 4% of them trucks, projected to reach 83,539 by 2043. The structure is 6,184 ft (1,884.9 m) long and 93 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesI-26 EB
CrossesS-46/HERIOT ST
LocationIn Charleston
RouteInterstate 26
CountyCharleston County
StateSouth Carolina
Coordinates32.81147, -79.95152
Functional classUrban Principal Arterial - Interstate

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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating47.5 US tons
Inventory rating20 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans76 (+19 approach)
Design loadHS 20
Structure length6,184 ft (1,884.9 m)
Longest span97 ft (29.5 m)
Deck width93 ft (28.4 m)
Roadway width93 ft (28.4 m)
Vertical clearance over deck17 ft (5.3 m)

Traffic and service

Average daily traffic60,100 (2023)
Projected traffic83,539 by 2043
Trucks4%
Lanes on structure6
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$40.6 million (2024 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-26 EB over S-46/HERIOT ST built?

It was built in 1968, making it 57 years old in 2025. It was reconstructed in 2005.

What condition is I-26 EB over S-46/HERIOT ST 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 August 2024.

How much traffic does I-26 EB over S-46/HERIOT ST carry?

About 60,100 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is I-26 EB over S-46/HERIOT ST?

The structure is 6,184 ft (1,884.9 m) long with a longest span of 97 ft (29.5 m) and a deck 93 ft wide.

Who owns I-26 EB over S-46/HERIOT ST?

It is owned by the State Highway Agency.