US Bridges

I-78 EB over Plainfield Ave&green Brk

Fair

Somerset County, New Jersey · 1.79 MI East of CR 531 · Structure no. 1817179

Built
1966
59 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
648 ft
6 main spans
Daily traffic
51,186
2024 count
Owner
State
State Highway Agency

About this bridge

I-78 EB over Plainfield Ave&green Brk is a steel stringer/multi-beam or girder carrying I-78 EB over Plainfield Ave&green Brk in Somerset County, New Jersey. It was built in 1966, so it is 59 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 51,186 vehicles a day, roughly 9% of them trucks, projected to reach 62,456 by 2044. The structure is 648 ft (197.5 m) long and 50 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI-78 EB
CrossesPlainfield Ave&green Brk
Location1.79 MI East of CR 531
RouteInterstate 78
CountySomerset County
StateNew Jersey
Coordinates40.66209, -74.42633
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating89 US tons
Inventory rating53 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans6
Design loadHS 20
Structure length648 ft (197.5 m)
Longest span118 ft (36 m)
Deck width50 ft (15.2 m)
Roadway width45 ft (13.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic51,186 (2024)
Projected traffic62,456 by 2044
Trucks9%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway and waterway
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 statusNot eligible for the National Register of Historic Places
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost$13,000 (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was I-78 EB over Plainfield Ave&green Brk built?

It was built in 1966, making it 59 years old in 2025.

What condition is I-78 EB over Plainfield Ave&green Brk 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 August 2024.

How much traffic does I-78 EB over Plainfield Ave&green Brk carry?

About 51,186 vehicles per day (2024 count), of which roughly 9% are trucks.

How long is I-78 EB over Plainfield Ave&green Brk?

The structure is 648 ft (197.5 m) long with a longest span of 118 ft (36 m) and a deck 50 ft wide.

Who owns I-78 EB over Plainfield Ave&green Brk?

It is owned by the State Highway Agency.