US Bridges

South Union Street over Swan Creek

Fair

Hunterdon County, New Jersey · 680 Ft. West Nj 29 · Structure no. 1000058

Built
1916
109 years old
Condition
Fair
inspected April 2023
Type
Arch - Deck
Concrete
Length
27 ft
1 main span
Daily traffic
3,776
2023 count
Owner
County
County Highway Agency

About this bridge

South Union Street over Swan Creek is a concrete arch - deck carrying South Union Street over Swan Creek in Hunterdon County, New Jersey. It was built in 1916, so it is 109 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 3,776 vehicles a day, roughly 1% of them trucks, projected to reach 4,607 by 2043. The structure is 27 ft (8.2 m) long and 51 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesSouth Union Street
CrossesSwan Creek
Location680 Ft. West Nj 29
RouteCity Street 0
Coordinates40.36425, -74.94425
Functional classUrban Local

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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 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 alignment9: Superior to present desirable criteria
Operating rating38 US tons
Inventory rating22 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckNot applicable
Main spans1
Design loadUnknown
Structure length27 ft (8.2 m)
Longest span27 ft (8.2 m)
Deck width51 ft (15.5 m)
Roadway width31 ft (9.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,776 (2023)
Projected traffic4,607 by 2043
Trucks1%
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$179,000 (2023 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was South Union Street over Swan Creek built?

It was built in 1916, making it 109 years old in 2025.

What condition is South Union Street 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 South Union Street over Swan Creek carry?

About 3,776 vehicles per day (2023 count), of which roughly 1% are trucks.

How long is South Union Street over Swan Creek?

The structure is 27 ft (8.2 m) long with a longest span of 27 ft (8.2 m) and a deck 51 ft wide.

Who owns South Union Street over Swan Creek?

It is owned by the County Highway Agency.