US Bridges

Mercer CR 524 over Gropp Lake

Fair

Mercer County, New Jersey · 0.28 Miles East of I-195 · Structure no. 1116150

Built
1931
94 years old, rebuilt 1986
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
45 ft
1 main span
Daily traffic
19,225
2023 count
Owner
State
State Highway Agency

About this bridge

Mercer CR 524 over Gropp Lake is a steel stringer/multi-beam or girder carrying Mercer CR 524 over Gropp Lake in Mercer County, New Jersey. It was built in 1931 and reconstructed in 1986, so it is 94 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 19,225 vehicles a day, roughly 4% of them trucks, projected to reach 22,925 by 2043. The structure is 45 ft (13.7 m) long and 60 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesMercer CR 524
CrossesGropp Lake
Location0.28 Miles East of I-195
RouteCounty Highway 524
CountyMercer County
StateNew Jersey
Coordinates40.18718, -74.68895
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.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 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 geometry9: Superior to present desirable criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59 US tons
Inventory rating35.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length45 ft (13.7 m)
Longest span41 ft (12.5 m)
Deck width60 ft (18.3 m)
Roadway width46 ft (14 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic19,225 (2023)
Projected traffic22,925 by 2043
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.1 mi (5 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Mercer CR 524 over Gropp Lake built?

It was built in 1931, making it 94 years old in 2025. It was reconstructed in 1986.

What condition is Mercer CR 524 over Gropp Lake 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 Mercer CR 524 over Gropp Lake carry?

About 19,225 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is Mercer CR 524 over Gropp Lake?

The structure is 45 ft (13.7 m) long with a longest span of 41 ft (12.5 m) and a deck 60 ft wide.

Who owns Mercer CR 524 over Gropp Lake?

It is owned by the State Highway Agency.