US Bridges

Chimney Rock RD over Middle Brook

Fair

Somerset County, New Jersey · 0.74 MI N of US 22 · Structure no. 18H0809

Built
1920
105 years old, rebuilt 1977
Condition
Fair
inspected September 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
46 ft
1 main span
Daily traffic
11,646
2023 count
Owner
County
County Highway Agency

About this bridge

Chimney Rock RD over Middle Brook is a prestressed concrete box beam or girders - multiple carrying Chimney Rock RD over Middle Brook in Somerset County, New Jersey. It was built in 1920 and reconstructed in 1977, so it is 105 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 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 11,646 vehicles a day, roughly 3% of them trucks, projected to reach 14,211 by 2043. The structure is 46 ft (14 m) long and 33 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

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CarriesChimney Rock RD
CrossesMiddle Brook
Location0.74 MI N of US 22
RouteCounty Highway 525
CountySomerset County
StateNew Jersey
Coordinates40.58412, -74.55776
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
Deck8 Very GoodNo problems noted.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourCountermeasures installed to correct a previously existing problem
Structural evaluation6: Equal to present minimum criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating83 US tons
Inventory rating50 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20 + Mod
Structure length46 ft (14 m)
Longest span38 ft (11.6 m)
Deck width33 ft (10.1 m)
Roadway width30 ft (9.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic11,646 (2023)
Projected traffic14,211 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 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 proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$397,000 (2023 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Chimney Rock RD over Middle Brook built?

It was built in 1920, making it 105 years old in 2025. It was reconstructed in 1977.

What condition is Chimney Rock RD over Middle 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 Chimney Rock RD over Middle Brook carry?

About 11,646 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Chimney Rock RD over Middle Brook?

The structure is 46 ft (14 m) long with a longest span of 38 ft (11.6 m) and a deck 33 ft wide.

Who owns Chimney Rock RD over Middle Brook?

It is owned by the County Highway Agency.