US Bridges

County Route 523 over Walnut Brook

Fair

Hunterdon County, New Jersey · 0.14 MI East of JCT Nj 12 · Structure no. 1000016

Built
1934
91 years old
Condition
Fair
inspected March 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
29 ft
1 main span
Daily traffic
5,908
2023 count
Owner
County
County Highway Agency

About this bridge

County Route 523 over Walnut Brook is a steel stringer/multi-beam or girder carrying County Route 523 over Walnut Brook in Hunterdon County, New Jersey. It was built in 1934, so it is 91 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 5,908 vehicles a day, roughly 4% of them trucks, projected to reach 7,209 by 2043. The structure is 29 ft (8.8 m) long and 37 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesCounty Route 523
CrossesWalnut Brook
Location0.14 MI East of JCT Nj 12
RouteCounty Highway 523
CountyHunterdon County
StateNew Jersey
Coordinates40.50501, -74.86923
Functional classUrban Minor Arterial

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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating58 US tons
Inventory rating35.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length29 ft (8.8 m)
Longest span24 ft (7.3 m)
Deck width37 ft (11.4 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,908 (2023)
Projected traffic7,209 by 2043
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusEligible for the National Register of Historic Places
Work proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was County Route 523 over Walnut Brook built?

It was built in 1934, making it 91 years old in 2025.

What condition is County Route 523 over Walnut 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 2023.

How much traffic does County Route 523 over Walnut Brook carry?

About 5,908 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is County Route 523 over Walnut Brook?

The structure is 29 ft (8.8 m) long with a longest span of 24 ft (7.3 m) and a deck 37 ft wide.

Who owns County Route 523 over Walnut Brook?

It is owned by the County Highway Agency.