US Bridges

I85 & US15 Nbl over SR1637 & Southern RR

Fair

Durham County, North Carolina · 0.33 Mi. N. Jct. SR1632 · Structure no. 000000000630216

Built
1956
69 years old, rebuilt 1996
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
209 ft
4 main spans
Daily traffic
21,250
2020 count
Owner
State
State Highway Agency

About this bridge

I85 & US15 Nbl over SR1637 & Southern RR is a steel stringer/multi-beam or girder carrying I85 & US15 Nbl over SR1637 & Southern RR in Durham County, North Carolina. It was built in 1956 and reconstructed in 1996, so it is 69 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 21,250 vehicles a day, roughly 16% of them trucks, projected to reach 42,500 by 2040. The structure is 209 ft (63.7 m) long and 43 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

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CarriesI85 & US15 Nbl
CrossesSR1637 & Southern RR
Location0.33 Mi. N. Jct. SR1632
RouteInterstate 85
CountyDurham County
StateNorth Carolina
Coordinates36.04843, -78.81096
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
Deck8 Very GoodNo problems noted.
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 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 geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating80.9 US tons
Inventory rating48 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20 + Mod
Structure length209 ft (63.7 m)
Longest span51 ft (15.5 m)
Deck width43 ft (13.1 m)
Roadway width40 ft (12.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic21,250 (2020)
Projected traffic42,500 by 2040
Trucks16%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway and railroad
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 proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was I85 & US15 Nbl over SR1637 & Southern RR built?

It was built in 1956, making it 69 years old in 2025. It was reconstructed in 1996.

What condition is I85 & US15 Nbl over SR1637 & Southern RR 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 I85 & US15 Nbl over SR1637 & Southern RR carry?

About 21,250 vehicles per day (2020 count), of which roughly 16% are trucks.

How long is I85 & US15 Nbl over SR1637 & Southern RR?

The structure is 209 ft (63.7 m) long with a longest span of 51 ft (15.5 m) and a deck 43 ft wide.

Who owns I85 & US15 Nbl over SR1637 & Southern RR?

It is owned by the State Highway Agency.