US Bridges

Mountain Blvd. over Stony Brook

Fair

Somerset County, New Jersey · At CR 531 JCT · Structure no. 18L1011

Built
1958
67 years old
Condition
Fair
inspected October 2023
Type
Slab
Concrete
Length
28 ft
1 main span
Daily traffic
13,979
2023 count
Owner
County
County Highway Agency

About this bridge

Mountain Blvd. over Stony Brook is a concrete slab carrying Mountain Blvd. over Stony Brook in Somerset County, New Jersey. It was built in 1958, so it is 67 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 13,979 vehicles a day, roughly 4% of them trucks, projected to reach 17,058 by 2043. The structure is 28 ft (8.5 m) long and 53 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesMountain Blvd.
CrossesStony Brook
LocationAt CR 531 JCT
RouteCounty Highway 527
CountySomerset County
StateNew Jersey
Coordinates40.63743, -74.45276
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
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 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 geometry6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating47 US tons
Inventory rating28 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20 + Mod
Structure length28 ft (8.5 m)
Longest span27 ft (8.2 m)
Deck width53 ft (16.2 m)
Roadway width37 ft (11.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic13,979 (2023)
Projected traffic17,058 by 2043
Trucks4%
Lanes on structure2
Traffic directionOne-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 statusHistorical significance not determinable at this time
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost$406,000 (2023 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Mountain Blvd. over Stony Brook built?

It was built in 1958, making it 67 years old in 2025.

What condition is Mountain Blvd. over Stony 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 Blvd. over Stony Brook carry?

About 13,979 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Mountain Blvd. over Stony Brook?

The structure is 28 ft (8.5 m) long with a longest span of 27 ft (8.2 m) and a deck 53 ft wide.

Who owns Mountain Blvd. over Stony Brook?

It is owned by the County Highway Agency.