US Bridges

I-78 EB over Nj 173

Fair

Hunterdon County, New Jersey · At Exit 7 of I-78 · Structure no. 1014150

Built
1959
66 years old, rebuilt 1984
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
93 ft
1 main span
Daily traffic
50,775
2024 count
Owner
State
State Highway Agency

About this bridge

I-78 EB over Nj 173 is a steel stringer/multi-beam or girder carrying I-78 EB over Nj 173 in Hunterdon County, New Jersey. It was built in 1959 and reconstructed in 1984, so it is 66 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 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 50,775 vehicles a day, roughly 9% of them trucks, projected to reach 60,930 by 2044. The structure is 93 ft (28.3 m) long and 58 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI-78 EB
CrossesNj 173
LocationAt Exit 7 of I-78
RouteInterstate 78
CountyHunterdon County
StateNew Jersey
Coordinates40.65995, -75.07093
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.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJuly 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 rating110.1 US tons
Inventory rating61 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length93 ft (28.3 m)
Longest span89 ft (27.1 m)
Deck width58 ft (17.8 m)
Roadway width51 ft (15.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50,775 (2024)
Projected traffic60,930 by 2044
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 proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$350,000 (2024 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-78 EB over Nj 173 built?

It was built in 1959, making it 66 years old in 2025. It was reconstructed in 1984.

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

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

About 50,775 vehicles per day (2024 count), of which roughly 9% are trucks.

How long is I-78 EB over Nj 173?

The structure is 93 ft (28.3 m) long with a longest span of 89 ft (27.1 m) and a deck 58 ft wide.

Who owns I-78 EB over Nj 173?

It is owned by the State Highway Agency.