US Bridges

Locktwn-Flemington over Plum Brook

Good

Hunterdon County, New Jersey · 1.1 MI West of CR 579 · Structure no. 100D388

Built
2004
21 years old
Condition
Good
inspected April 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
28 ft
1 main span
Daily traffic
339
2023 count
Owner
County
County Highway Agency

About this bridge

Locktwn-Flemington over Plum Brook is a steel stringer/multi-beam or girder carrying Locktwn-Flemington over Plum Brook in Hunterdon County, New Jersey. It was built in 2004, so it is 21 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 good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 339 vehicles a day, roughly 3% of them trucks, projected to reach 407 by 2043. The structure is 28 ft (8.5 m) long and 25 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

CarriesLocktwn-Flemington
CrossesPlum Brook
Location1.1 MI West of CR 579
Coordinates40.48409, -74.94353
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
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 rating57 US tons
Inventory rating34 US tons

Structure

MaterialSteel
DeckCorrugated steel
Main spans1
Design loadHS 25 or greater
Structure length28 ft (8.5 m)
Longest span27 ft (8.2 m)
Deck width25 ft (7.7 m)
Roadway width25 ft (7.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic339 (2023)
Projected traffic407 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Locktwn-Flemington over Plum Brook built?

It was built in 2004, making it 21 years old in 2025.

What condition is Locktwn-Flemington over Plum Brook in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in April 2023.

How much traffic does Locktwn-Flemington over Plum Brook carry?

About 339 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Locktwn-Flemington over Plum Brook?

The structure is 28 ft (8.5 m) long with a longest span of 27 ft (8.2 m) and a deck 25 ft wide.

Who owns Locktwn-Flemington over Plum Brook?

It is owned by the County Highway Agency.