US Bridges

Zion-Wertsville RD over Rock Brook

Fair

Somerset County, New Jersey · 0.1 MI No. Hollow Road · Structure no. 18B0301

Built
1825
200 years old, rebuilt 2023
Condition
Fair
inspected December 2023
Type
Slab
Concrete
Length
41 ft
1 main span
Daily traffic
903
2023 count
Owner
County
County Highway Agency

About this bridge

Zion-Wertsville RD over Rock Brook is a concrete slab carrying Zion-Wertsville RD over Rock Brook in Somerset County, New Jersey. It was built in 1825 and reconstructed in 2023, so it is 200 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 903 vehicles a day, roughly 1% of them trucks, projected to reach 1,084 by 2043. The structure is 41 ft (12.5 m) long and 17 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesZion-Wertsville RD
CrossesRock Brook
Location0.1 MI No. Hollow Road
CountySomerset County
StateNew Jersey
Coordinates40.4397, -74.73943
Functional classRural Local

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.
Superstructure8 Very GoodNo problems noted.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionDecember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating88 US tons
Inventory rating53 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1 (+2 approach)
Design loadHS 25 or greater
Structure length41 ft (12.5 m)
Longest span15 ft (4.6 m)
Deck width17 ft (5.2 m)
Roadway width14 ft (4.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic903 (2023)
Projected traffic1,084 by 2043
Trucks1%
Lanes on structure1
Traffic directionOne-lane bridge for two-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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Zion-Wertsville RD over Rock Brook built?

It was built in 1825, making it 200 years old in 2025. It was reconstructed in 2023.

What condition is Zion-Wertsville RD over Rock 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 December 2023.

How much traffic does Zion-Wertsville RD over Rock Brook carry?

About 903 vehicles per day (2023 count), of which roughly 1% are trucks.

How long is Zion-Wertsville RD over Rock Brook?

The structure is 41 ft (12.5 m) long with a longest span of 15 ft (4.6 m) and a deck 17 ft wide.

Who owns Zion-Wertsville RD over Rock Brook?

It is owned by the County Highway Agency.