US Bridges

I-78 over Diamond Hill RD (co 655)

Fair

Union County, New Jersey · 1.8 MI E of I-78 Exit 43 · Structure no. 2010154

Built
1986
39 years old
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
183 ft
3 main spans
Daily traffic
105,635
2024 count
Owner
State
State Highway Agency

About this bridge

I-78 over Diamond Hill RD (co 655) is a steel stringer/multi-beam or girder carrying I-78 over Diamond Hill RD (co 655) in Union County, New Jersey. It was built in 1986, so it is 39 years old, younger 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 105,635 vehicles a day, roughly 9% of them trucks, projected to reach 128,875 by 2044. The structure is 183 ft (55.8 m) long and 126 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI-78
CrossesDiamond Hill RD (co 655)
Location1.8 MI E of I-78 Exit 43
RouteInterstate 78
CountyUnion County
StateNew Jersey
Coordinates40.67312, -74.40664
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating110.1 US tons
Inventory rating60 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length183 ft (55.8 m)
Longest span98 ft (29.9 m)
Deck width126 ft (38.3 m)
Roadway width119 ft (36.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic105,635 (2024)
Projected traffic128,875 by 2044
Trucks9%
Lanes on structure6
Traffic directionTwo-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 proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-78 over Diamond Hill RD (co 655) built?

It was built in 1986, making it 39 years old in 2025.

What condition is I-78 over Diamond Hill RD (co 655) 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 April 2024.

How much traffic does I-78 over Diamond Hill RD (co 655) carry?

About 105,635 vehicles per day (2024 count), of which roughly 9% are trucks.

How long is I-78 over Diamond Hill RD (co 655)?

The structure is 183 ft (55.8 m) long with a longest span of 98 ft (29.9 m) and a deck 126 ft wide.

Who owns I-78 over Diamond Hill RD (co 655)?

It is owned by the State Highway Agency.