US Bridges

Nj Route 31 over Spruce Run

Fair

Hunterdon County, New Jersey · 4.7 MI N of I-78 JCT · Structure no. 1013154

Built
1930
95 years old
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
72 ft
2 main spans
Daily traffic
24,293
2023 count
Owner
State
State Highway Agency

About this bridge

Nj Route 31 over Spruce Run is a steel stringer/multi-beam or girder carrying Nj Route 31 over Spruce Run in Hunterdon County, New Jersey. It was built in 1930, so it is 95 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 24,293 vehicles a day, roughly 4% of them trucks, projected to reach 29,152 by 2043. The structure is 72 ft (21.9 m) long and 44 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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CarriesNj Route 31
CrossesSpruce Run
Location4.7 MI N of I-78 JCT
RouteState Highway 31
CountyHunterdon County
StateNew Jersey
Coordinates40.68715, -74.93401
Functional classUrban Other Principal 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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating42 US tons
Inventory rating25 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length72 ft (21.9 m)
Longest span34 ft (10.4 m)
Deck width44 ft (13.5 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic24,293 (2023)
Projected traffic29,152 by 2043
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 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 Route 31 over Spruce Run built?

It was built in 1930, making it 95 years old in 2025.

What condition is Nj Route 31 over Spruce Run 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 2023.

How much traffic does Nj Route 31 over Spruce Run carry?

About 24,293 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Nj Route 31 over Spruce Run?

The structure is 72 ft (21.9 m) long with a longest span of 34 ft (10.4 m) and a deck 44 ft wide.

Who owns Nj Route 31 over Spruce Run?

It is owned by the State Highway Agency.