US Bridges

Mercer ST over Rockaway River

Fair

Morris County, New Jersey · .1 Mile East of Union St. · Structure no. 1401016

Built
1910
115 years old
Condition
Fair
inspected June 2023
Type
Arch - Deck
Concrete
Length
45 ft
1 main span
Daily traffic
6,446
2023 count
Owner
County
County Highway Agency

About this bridge

Mercer ST over Rockaway River is a concrete arch - deck carrying Mercer ST over Rockaway River in Morris County, New Jersey. It was built in 1910, so it is 115 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 6,446 vehicles a day, roughly 3% of them trucks, projected to reach 7,865 by 2043. The structure is 45 ft (13.7 m) long and 50 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesMercer ST
CrossesRockaway River
Location.1 Mile East of Union St.
RouteCity Street 0
CountyMorris County
StateNew Jersey
Coordinates40.88528, -74.55181
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
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJune 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 adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating47 US tons
Inventory rating28 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckNot applicable
Main spans1
Design loadUnknown
Structure length45 ft (13.7 m)
Longest span45 ft (13.7 m)
Deck width50 ft (15.2 m)
Roadway width35 ft (10.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,446 (2023)
Projected traffic7,865 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$260,000 (2023 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Mercer ST over Rockaway River built?

It was built in 1910, making it 115 years old in 2025.

What condition is Mercer ST over Rockaway River 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 June 2023.

How much traffic does Mercer ST over Rockaway River carry?

About 6,446 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Mercer ST over Rockaway River?

The structure is 45 ft (13.7 m) long with a longest span of 45 ft (13.7 m) and a deck 50 ft wide.

Who owns Mercer ST over Rockaway River?

It is owned by the County Highway Agency.