US Bridges

I77 Nbl over Southern Railway

Fair

Iredell County, North Carolina · 0.1 Mi. N. Jct. US70 · Structure no. 000000000970145

Built
1957
68 years old, rebuilt 1964
Condition
Fair
inspected March 2024
Type
Tee Beam
Concrete
Length
180 ft
5 main spans
Daily traffic
27,500
2020 count
Owner
State
State Highway Agency

About this bridge

I77 Nbl over Southern Railway is a concrete tee beam carrying I77 Nbl over Southern Railway in Iredell County, North Carolina. It was built in 1957 and reconstructed in 1964, so it is 68 years old, older than the North Carolina average of 38.7 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 27,500 vehicles a day, roughly 16% of them trucks, projected to reach 55,000 by 2040. The structure is 180 ft (54.8 m) long and 45 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesI77 Nbl
CrossesSouthern Railway
Location0.1 Mi. N. Jct. US70
RouteInterstate 77
CountyIredell County
StateNorth Carolina
Coordinates35.77405, -80.86321
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment8: Equal to present desirable criteria
Operating rating62.9 US tons
Inventory rating36.9 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20 + Mod
Structure length180 ft (54.8 m)
Longest span47 ft (14.3 m)
Deck width45 ft (13.8 m)
Roadway width40 ft (12.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic27,500 (2020)
Projected traffic55,000 by 2040
Trucks16%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesRailroad
Detour if closed0.6 mi (1 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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was I77 Nbl over Southern Railway built?

It was built in 1957, making it 68 years old in 2025. It was reconstructed in 1964.

What condition is I77 Nbl over Southern Railway 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 March 2024.

How much traffic does I77 Nbl over Southern Railway carry?

About 27,500 vehicles per day (2020 count), of which roughly 16% are trucks.

How long is I77 Nbl over Southern Railway?

The structure is 180 ft (54.8 m) long with a longest span of 47 ft (14.3 m) and a deck 45 ft wide.

Who owns I77 Nbl over Southern Railway?

It is owned by the State Highway Agency.