US Bridges

Nj 4 over Flat Rock Brook

Fair

Bergen County, New Jersey · 0.5 MI East of Nj Rt 93 · Structure no. 0206181

Built
1931
94 years old, rebuilt 2013
Condition
Fair
inspected March 2024
Type
Tee Beam
Prestressed Concrete
Length
25 ft
1 main span
Daily traffic
84,845
2024 count
Owner
State
State Highway Agency

About this bridge

Nj 4 over Flat Rock Brook is a prestressed concrete tee beam carrying Nj 4 over Flat Rock Brook in Bergen County, New Jersey. It was built in 1931 and reconstructed in 2013, so it is 94 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 84,845 vehicles a day, roughly 5% of them trucks, projected to reach 103,620 by 2044. The structure is 25 ft (7.6 m) long and 99 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesNj 4
CrossesFlat Rock Brook
Location0.5 MI East of Nj Rt 93
RouteState Highway 4
CountyBergen County
StateNew Jersey
Coordinates40.87438, -73.97376
Functional classUrban Principal Arterial - Other Freeway or Expressway

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.
Superstructure8 Very GoodNo problems noted.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
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 rating106.8 US tons
Inventory rating106.8 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHL 93
Structure length25 ft (7.6 m)
Longest span21 ft (6.4 m)
Deck width99 ft (30.2 m)
Roadway width68 ft (20.7 m)
Vertical clearance over deck100 ft (30.5 m)

Traffic and service

Average daily traffic84,845 (2024)
Projected traffic103,620 by 2044
Trucks5%
Lanes on structure5
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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—
NavigationNo navigation control on waterway

Frequently asked questions

When was Nj 4 over Flat Rock Brook built?

It was built in 1931, making it 94 years old in 2025. It was reconstructed in 2013.

What condition is Nj 4 over Flat Rock Brook 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 March 2024.

How much traffic does Nj 4 over Flat Rock Brook carry?

About 84,845 vehicles per day (2024 count), of which roughly 5% are trucks.

How long is Nj 4 over Flat Rock Brook?

The structure is 25 ft (7.6 m) long with a longest span of 21 ft (6.4 m) and a deck 99 ft wide.

Who owns Nj 4 over Flat Rock Brook?

It is owned by the State Highway Agency.