HistoricBridges.org Menu: HistoricBridges.org Menu:

We Recommend:
Bach Steel - Experts at historic truss bridge restoration.

HistoricBridges.org: Bridge Browser

Jackson Road Bridge

Jackson Road Bridge

Primary Photographer(s): Nathan Holth

Bridge Documented: November 7, 2015

View Photos
and Videos
View Maps
and Links

Rural: Somerset County, New Jersey: United States
Construction Date and Builder / Engineer
1927 By Builder/Contractor: Unknown
Rehabilitation Date
Main Span Length
57.0 Feet (17.4 Meters)
Structure Length
62.0 Feet (18.9 Meters)
Roadway Width
21.3 Feet (6.49 Meters)
1 Main Span(s)
Inventory Number

Historic Significance Rating (HSR)
View Information About HSR Ratings

Bridge Documentation

View Archived National Bridge Inventory Report - Has Additional Details and Evaluation

This is a traditionally composed riveted truss bridge. However, its truss configuration is that of a Warren truss with no vertical members. Because nearly all Warren truss bridges have vertical members, this truss is therefore a rare example of one without verticals.

This bridge is listed in the National Bridge Inventory as a County-Owned, taxpayer funded bridge. Yet the bridge connects a county road (Branch Road) to a road that immediately at the end of the bridge is posted as a private road. Its unclear how such an unusual situation came to be (a public taxpayer funded bridge serving a private driveway) but for this reason it is recommended that visitors to the bridge approach from the west on Branch Road. The bridge itself remains listed as a public, taxpayer funded bridge in the National Bridge Inventory however, so visitors to this bridge should understand that they have a legal right to walk on the bridge deck, even if the road east of the bridge is private.

Information and Findings From New Jersey's Historic Bridge Inventory


The skewed rivet-connected 4-panel Warren pony truss bridge is a complete example of its type, but its design is typical of the period. It is composed of channels and plates for the chords, and of angles joined by battens for the diagonals. The Warren is the most common 20thcentury truss type for highway bridges. The newest of the 10 Warren pony truss spans in the county, it is an extremely well preserved example of the historically significant bridge type, and it is thus notable.


The single-lane bridge spans the river and connects Branch Road on the west bank with a private lane (Jackson Road). The surrounding area is hilly and rural with pastures, wooded lots, and scattered 19th- and 20th-century residences.

Physical Description

The skewed 62'-long riveted Warren pony truss bridge is supported on a concrete substructure. The span is extremely well preserved. The upper chords and inclined end posts are built up box members with channels with cover plate and lacing. The diagonals are toe-down angles with battens, and the lower chords are toe-up angles with battens. Asymmetrical gusset plates are placed on both sides of the lower panel points, and they too are stiffened with a batten plate. The floor beams and stringers are rolled I sections. Lattice railings are still in place on the inside face of the trusses. As complete as the trusses is the rural setting of the bridge, which services and unimproved road.

Historical and Technological Significance

The Warren pony truss bridge on Jackson Road was built in 1927, and it is the latest of the surviving examples of metal truss bridges in the county. While exhibiting no innovative or patented details, the span is technologically and historically significant as a well preserved survivor of the last years of metal truss bridge erection in the area (criterion C). It was apparently designed by County Engineer Oscar Smith, Jr., who succeeded longtime County Engineer Joshua Doughty, and it was built at a time when most county-designed spans were encased stringers. There is no indication that this bridge was moved to Jackson Road from another location. Prior to the widespread acceptance of rolled steel stringer and reinforced concrete arch bridges in the 1910s, the Warren pony truss was the most common early-20th century highway bridge for crossings of less than 100'. The Warren truss bridge type was patented in 1848 by two British engineers, James Warren and Willoughby Monzani. It differed from other trusses in that it did not have a vertical (compression) member and that alternate diagonals slope in opposite directions. Because some of those diagonals are compression members, the design was not well suited for pinned connections. With the perfection of the portable pneumatic equipment in the late-19th century, field riveting was possible, and the simple but rigid Warren truss came to the fore during the 1890s. During the early 20th century, steel Warren trusses appeared in rapidly growing numbers, and were used for both highway and railroad spans. However, by the end of the 1920s. few, if any, metal pony truss highway bridges were being built in New Jersey.

Boundary Description and Justification

The bridge is evaluated as individually distinguished, although its rural setting does offer fine integrity of setting. The significant boundary is limited to the span itself, both the superstructure and substructure.


Somerset County Engineer: Bridge File: E141. Musti, J. Somerset County New Jersey 1688-1930. Camden, N.J., 1930.

Bridge Considered Historic By Survey: Yes


Photo Galleries and Videos: Jackson Road Bridge


View Photo Gallery

Bridge Photo-Documentation

Original / Full Size Photos
A collection of overview and detail photos. This gallery offers photos in the highest available resolution and file size in a touch-friendly popup viewer.
Alternatively, Browse Without Using Viewer


View Photo Gallery

Bridge Photo-Documentation

Mobile Optimized Photos
A collection of overview and detail photos. This gallery features data-friendly, fast-loading photos in a touch-friendly popup viewer.
Alternatively, Browse Without Using Viewer


Maps and Links: Jackson Road Bridge

The road east of this bridge is posted as private, so approach this bridge from the west.

Coordinates (Latitude, Longitude):

Search For Additional Bridge Listings:

Bridgehunter.com: View listed bridges within 0.5 miles (0.8 kilometers) of this bridge.

Bridgehunter.com: View listed bridges within 10 miles (16 kilometers) of this bridge.

HistoricBridges.org Bridge Browser: View listed bridges within 0.5 miles (0.8 kilometers) of this bridge.

HistoricBridges.org Bridge Browser: View listed bridges within 10 miles (16 kilometers) of this bridge.

2021 National Bridge Inventory: View listed bridges within 0.5 miles (0.8 kilometers) of this bridge.

Additional Maps:

Google Maps

Google Streetview (If Available)

Bing Maps


GeoHack (Additional Links and Coordinates)

Apple Maps (Via DuckDuckGo Search)

Apple Maps (Apple devices only)


HERE We Go Maps

ACME Mapper

Waze Map

Android: Open Location In Your Map or GPS App

Flickr Gallery (Find Nearby Photos)

Wikimedia Commons (Find Nearby Photos)

Directions Via Sygic For Android

Directions Via Sygic For iOS and Android Dolphin Browser

USGS National Map (United States Only)

Historical USGS Topo Maps (United States Only)

Historic Aerials (United States Only)

CalTopo Maps (United States Only)

Home Top


About - Contact

© Copyright 2003-2023, HistoricBridges.org. All Rights Reserved. Disclaimer: HistoricBridges.org is a volunteer group of private citizens. HistoricBridges.org is NOT a government agency, does not represent or work with any governmental agencies, nor is it in any way associated with any government agency or any non-profit organization. While we strive for accuracy in our factual content, HistoricBridges.org offers no guarantee of accuracy. Information is provided "as is" without warranty of any kind, either expressed or implied. Information could include technical inaccuracies or errors of omission. Opinions and commentary are the opinions of the respective HistoricBridges.org member who made them and do not necessarily represent the views of anyone else, including any outside photographers whose images may appear on the page in which the commentary appears. HistoricBridges.org does not bear any responsibility for any consequences resulting from the use of this or any other HistoricBridges.org information. Owners and users of bridges have the responsibility of correctly following all applicable laws, rules, and regulations, regardless of any HistoricBridges.org information.

Admin Login