US Bridges

Mountain Ave over Peters Brook

Fair

Somerset County, New Jersey · .24 MI So. of US 22 · Structure no. 18F0809

Built
1901
124 years old, rebuilt 1977
Condition
Fair
inspected October 2023
Type
Slab
Prestressed Concrete
Length
74 ft
2 main spans
Daily traffic
5,455
2023 count
Owner
County
County Highway Agency

About this bridge

Mountain Ave over Peters Brook is a prestressed concrete slab carrying Mountain Ave over Peters Brook in Somerset County, New Jersey. It was built in 1901 and reconstructed in 1977, so it is 124 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 5,455 vehicles a day, roughly 3% of them trucks, projected to reach 6,546 by 2043. The structure is 74 ft (22.6 m) long and 47 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesMountain Ave
CrossesPeters Brook
Location.24 MI So. of US 22
RouteCounty Highway 643
CountySomerset County
StateNew Jersey
Coordinates40.57797, -74.61913
Functional classUrban Collector

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.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating79 US tons
Inventory rating40 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length74 ft (22.6 m)
Longest span35 ft (10.7 m)
Deck width47 ft (14.3 m)
Roadway width34 ft (10.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,455 (2023)
Projected traffic6,546 by 2043
Trucks3%
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 statusNot eligible for the National Register of Historic Places
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost$462,000 (2023 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Mountain Ave over Peters Brook built?

It was built in 1901, making it 124 years old in 2025. It was reconstructed in 1977.

What condition is Mountain Ave over Peters 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 October 2023.

How much traffic does Mountain Ave over Peters Brook carry?

About 5,455 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Mountain Ave over Peters Brook?

The structure is 74 ft (22.6 m) long with a longest span of 35 ft (10.7 m) and a deck 47 ft wide.

Who owns Mountain Ave over Peters Brook?

It is owned by the County Highway Agency.