US Bridges

Mt Airy RD (CR525) over Harrisons Brook

Fair

Somerset County, New Jersey · 1.53 MI North of I-78 · Structure no. 18G1110

Built
1971
54 years old
Condition
Fair
inspected September 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
53 ft
1 main span
Daily traffic
23,883
2023 count
Owner
County
County Highway Agency

About this bridge

Mt Airy RD (CR525) over Harrisons Brook is a prestressed concrete box beam or girders - multiple carrying Mt Airy RD (CR525) over Harrisons Brook in Somerset County, New Jersey. It was built in 1971, so it is 54 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 fair condition with a lowest component rating of 6 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 23,883 vehicles a day, roughly 4% of them trucks, projected to reach 29,141 by 2043. The structure is 53 ft (16.2 m) long and 63 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesMt Airy RD (CR525)
CrossesHarrisons Brook
Location1.53 MI North of I-78
RouteCounty Highway 525
CountySomerset County
StateNew Jersey
Coordinates40.66781, -74.57367
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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46 US tons
Inventory rating27 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length53 ft (16.2 m)
Longest span47 ft (14.3 m)
Deck width63 ft (19.1 m)
Roadway width48 ft (14.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic23,883 (2023)
Projected traffic29,141 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 statusHistorical significance not determinable at this time
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost$496,000 (2023 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Mt Airy RD (CR525) over Harrisons Brook built?

It was built in 1971, making it 54 years old in 2025.

What condition is Mt Airy RD (CR525) over Harrisons 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 September 2023.

How much traffic does Mt Airy RD (CR525) over Harrisons Brook carry?

About 23,883 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Mt Airy RD (CR525) over Harrisons Brook?

The structure is 53 ft (16.2 m) long with a longest span of 47 ft (14.3 m) and a deck 63 ft wide.

Who owns Mt Airy RD (CR525) over Harrisons Brook?

It is owned by the County Highway Agency.