US Bridges

County Route 518 over Swan Creek

Fair

Hunterdon County, New Jersey · 0.15 Mile East of Nj 29 · Structure no. 100Y041

Built
1876
149 years old
Condition
Fair
inspected April 2023
Type
Arch - Deck
Masonry
Length
23 ft
1 main span
Daily traffic
4,456
2023 count
Owner
County
County Highway Agency

About this bridge

County Route 518 over Swan Creek is a masonry arch - deck carrying County Route 518 over Swan Creek in Hunterdon County, New Jersey. It was built in 1876, so it is 149 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 4,456 vehicles a day, roughly 3% of them trucks, projected to reach 5,438 by 2043. The structure is 23 ft (7 m) long and 34 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesCounty Route 518
CrossesSwan Creek
Location0.15 Mile East of Nj 29
RouteCounty Highway 518
CountyHunterdon County
StateNew Jersey
Coordinates40.36497, -74.93894
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 inspectionApril 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 geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating56 US tons
Inventory rating34 US tons

Structure

Structure typeArch - Deck
MaterialMasonry
DeckNot applicable
Main spans1
Design loadUnknown
Structure length23 ft (7 m)
Longest span23 ft (7 m)
Deck width34 ft (10.3 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,456 (2023)
Projected traffic5,438 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
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 statusEligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was County Route 518 over Swan Creek built?

It was built in 1876, making it 149 years old in 2025.

What condition is County Route 518 over Swan Creek 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 County Route 518 over Swan Creek carry?

About 4,456 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is County Route 518 over Swan Creek?

The structure is 23 ft (7 m) long with a longest span of 23 ft (7 m) and a deck 34 ft wide.

Who owns County Route 518 over Swan Creek?

It is owned by the County Highway Agency.