US Bridges

SR1121 over NC147

Fair

Durham County, North Carolina · 0.3 MI.N.SR2017 · Structure no. 000000000630206

Built
1973
52 years old
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
327 ft
2 main spans
Daily traffic
7,400
2021 count
Owner
State
State Highway Agency

About this bridge

SR1121 over NC147 is a steel continuous stringer/multi-beam or girder carrying SR1121 over NC147 in Durham County, North Carolina. It was built in 1973, so it is 52 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 7,400 vehicles a day, roughly 6% of them trucks, projected to reach 14,800 by 2040. The structure is 327 ft (99.6 m) long and 94 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesSR1121
CrossesNC147
Location0.3 MI.N.SR2017
RouteState Highway 1121
CountyDurham County
StateNorth Carolina
Coordinates35.9111, -78.86515
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJune 2023
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 geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating63.9 US tons
Inventory rating37.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2 (+2 approach)
Design loadHS 20 + Mod
Structure length327 ft (99.6 m)
Longest span130 ft (39.6 m)
Deck width94 ft (28.6 m)
Roadway width91 ft (27.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,400 (2021)
Projected traffic14,800 by 2040
Trucks6%
Lanes on structure6
Traffic directionTwo-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed1.9 mi (3 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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was SR1121 over NC147 built?

It was built in 1973, making it 52 years old in 2025.

What condition is SR1121 over NC147 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 June 2023.

How much traffic does SR1121 over NC147 carry?

About 7,400 vehicles per day (2021 count), of which roughly 6% are trucks.

How long is SR1121 over NC147?

The structure is 327 ft (99.6 m) long with a longest span of 130 ft (39.6 m) and a deck 94 ft wide.

Who owns SR1121 over NC147?

It is owned by the State Highway Agency.