US Bridges

Nj Route 18 over Njtpk

Fair

Middlesex County, New Jersey · 0.3 MI S of Int. 9 · Structure no. M082950

Built
1974
51 years old
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
681 ft
6 main spans
Daily traffic
109,977
2023 count
Owner
Toll Authority
State Toll Authority

About this bridge

Nj Route 18 over Njtpk is a steel stringer/multi-beam or girder carrying Nj Route 18 over Njtpk in Middlesex County, New Jersey. It was built in 1974, so it is 51 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 109,977 vehicles a day, roughly 4% of them trucks, projected to reach 134,193 by 2043. The structure is 681 ft (207.6 m) long and 95 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

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CarriesNj Route 18
CrossesNjtpk
Location0.3 MI S of Int. 9
RouteState Highway 18
CountyMiddlesex County
StateNew Jersey
Coordinates40.47324, -74.40954
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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating36.8 US tons
Inventory rating28.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans6
Design loadHS 20
Structure length681 ft (207.6 m)
Longest span134 ft (40.8 m)
Deck width95 ft (29 m)
Roadway width82 ft (25 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic109,977 (2023)
Projected traffic134,193 by 2043
Trucks4%
Lanes on structure6
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkNon-Interstate STRAHNET route

Ownership and planned work

OwnerState Toll Authority
Maintained byState Toll Authority
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$18.2 million
NavigationNot applicable (no waterway)

Frequently asked questions

When was Nj Route 18 over Njtpk built?

It was built in 1974, making it 51 years old in 2025.

What condition is Nj Route 18 over Njtpk 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 April 2023.

How much traffic does Nj Route 18 over Njtpk carry?

About 109,977 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Nj Route 18 over Njtpk?

The structure is 681 ft (207.6 m) long with a longest span of 134 ft (40.8 m) and a deck 95 ft wide.

Who owns Nj Route 18 over Njtpk?

It is owned by the State Toll Authority.