US Bridges

NC147S over Blackwell St.

Fair

Durham County, North Carolina · 0.2 MI.N.JCT.US501 · Structure no. 000000000630160

Built
1968
57 years old
Condition
Fair
inspected September 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
313 ft
5 main spans
Daily traffic
25,750
2020 count
Owner
State
State Highway Agency

About this bridge

NC147S over Blackwell St. is a steel stringer/multi-beam or girder carrying NC147S over Blackwell St. in Durham County, North Carolina. It was built in 1968, so it is 57 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 25,750 vehicles a day, roughly 12% of them trucks, projected to reach 51,500 by 2040. The structure is 313 ft (95.4 m) long and 56 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesNC147S
CrossesBlackwell St.
Location0.2 MI.N.JCT.US501
RouteState Highway 147
CountyDurham County
StateNorth Carolina
Coordinates35.99094, -78.906
Functional classUrban Principal Arterial - Other Freeway or Expressway

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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionSeptember 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 geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating71 US tons
Inventory rating42 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans5 (+2 approach)
Design loadHS 20 + Mod
Structure length313 ft (95.4 m)
Longest span95 ft (29 m)
Deck width56 ft (17.1 m)
Roadway width52 ft (16 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic25,750 (2020)
Projected traffic51,500 by 2040
Trucks12%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed0.6 mi (1 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 proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was NC147S over Blackwell St. built?

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

What condition is NC147S over Blackwell 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 September 2023.

How much traffic does NC147S over Blackwell St. carry?

About 25,750 vehicles per day (2020 count), of which roughly 12% are trucks.

How long is NC147S over Blackwell St.?

The structure is 313 ft (95.4 m) long with a longest span of 95 ft (29 m) and a deck 56 ft wide.

Who owns NC147S over Blackwell St.?

It is owned by the State Highway Agency.