US Bridges

US 46 over Mine Brook

Fair

Morris County, New Jersey · 0.79 MI E of CR 604 · Structure no. 1407152

Built
1921
104 years old, rebuilt 1986
Condition
Fair
inspected March 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
36 ft
1 main span
Daily traffic
13,131
2023 count
Owner
State
State Highway Agency

About this bridge

US 46 over Mine Brook is a steel stringer/multi-beam or girder carrying US 46 over Mine Brook in Morris County, New Jersey. It was built in 1921 and reconstructed in 1986, so it is 104 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 13,131 vehicles a day, roughly 4% of them trucks, projected to reach 16,022 by 2043. The structure is 36 ft (11 m) long and 94 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesUS 46
CrossesMine Brook
Location0.79 MI E of CR 604
RouteU.S. Route 46
CountyMorris County
StateNew Jersey
Coordinates40.84451, -74.81098
Functional classUrban Other Principal 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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating66 US tons
Inventory rating39 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length36 ft (11 m)
Longest span32 ft (9.8 m)
Deck width94 ft (28.8 m)
Roadway width80 ft (24.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic13,131 (2023)
Projected traffic16,022 by 2043
Trucks4%
Lanes on structure6
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was US 46 over Mine Brook built?

It was built in 1921, making it 104 years old in 2025. It was reconstructed in 1986.

What condition is US 46 over Mine 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 March 2023.

How much traffic does US 46 over Mine Brook carry?

About 13,131 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is US 46 over Mine Brook?

The structure is 36 ft (11 m) long with a longest span of 32 ft (9.8 m) and a deck 94 ft wide.

Who owns US 46 over Mine Brook?

It is owned by the State Highway Agency.