US Bridges

I-78 EB over Nj Rt. 173 EB

Fair

Hunterdon County, New Jersey · At I-78 Exit 15 · Structure no. 1016150

Built
1958
67 years old
Condition
Fair
inspected June 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
73 ft
1 main span
Daily traffic
58,431
2022 count
Owner
State
State Highway Agency

About this bridge

I-78 EB over Nj Rt. 173 EB is a prestressed concrete stringer/multi-beam or girder carrying I-78 EB over Nj Rt. 173 EB in Hunterdon County, New Jersey. It was built in 1958, so it is 67 years old, older than the New Jersey average of 58.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 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 58,431 vehicles a day, roughly 9% of them trucks, projected to reach 71,297 by 2042. The structure is 73 ft (22.3 m) long and 58 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI-78 EB
CrossesNj Rt. 173 EB
LocationAt I-78 Exit 15
RouteInterstate 78
CountyHunterdon County
StateNew Jersey
Coordinates40.6313, -74.91948
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment8: Equal to present desirable criteria
Operating rating78 US tons
Inventory rating47 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length73 ft (22.3 m)
Longest span68 ft (20.7 m)
Deck width58 ft (17.7 m)
Roadway width51 ft (15.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic58,431 (2022)
Projected traffic71,297 by 2042
Trucks9%
Lanes on structure4
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 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 statusHistorical significance not determinable at this time
Work proposedDeck rehabilitation with only incidental widening
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-78 EB over Nj Rt. 173 EB built?

It was built in 1958, making it 67 years old in 2025.

What condition is I-78 EB over Nj Rt. 173 EB 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 2024.

How much traffic does I-78 EB over Nj Rt. 173 EB carry?

About 58,431 vehicles per day (2022 count), of which roughly 9% are trucks.

How long is I-78 EB over Nj Rt. 173 EB?

The structure is 73 ft (22.3 m) long with a longest span of 68 ft (20.7 m) and a deck 58 ft wide.

Who owns I-78 EB over Nj Rt. 173 EB?

It is owned by the State Highway Agency.