New Hope-Lambertville Bridge repairs extended due to unforeseen structural issues

LAMBERTVILLE, NJ (Hunterdon County) – The current vehicular and pedestrian travel restrictions at the 120-year-old New Hope-Lambertville Toll-Supported Bridge must be extended several more months due to an unforeseen structural condition in one of the bridge’s six spans, according to the Delaware River Joint Toll Bridge Commission (DRJTBC).

The bridge has been undergoing a comprehensive rehabilitation project throughout much of this year. To carry out the project, a New Jersey-bound traffic detour has been in effect since late January, and pedestrian crossings have been restricted to a temporary walkway on the bridge’s roadway deck since mid-July.

It was originally anticipated that the structure could be reopened this fall, allowing for a return of two-way traffic on the bridge’s roadway deck and for pedestrians to use a soon-to-be-completed new walkway facility.

However, the discovery of a deteriorated critical structural connection in the bridge’s second span from the Pennsylvania side will postpone the walkway opening until sometime in December. Meanwhile, the current New Jersey-bound vehicular traffic detour will likely need to be extended into early 2025, when an uninterrupted two-week-long shutdown of the bridge will be implemented to fully repair the deteriorated structural connection.

“We understand the importance this bridge has to New Hope and Lambertville, and we are committed to resolving this issue as quickly and safely as possible,” said DRJTBC Executive Director Joe Resta. “The public’s safety and the bridge’s structural integrity are top priorities.”

A Critical Issue

At issue is a critical connection on the lower downstream chord of the bridge’s second truss span from the Pennsylvania side. A 4-inch-diameter, 18-inch-long steel pin that supports a joint connecting 11 structural steel members has rusted and worn to the point where it poses a potential risk of failure under heavy load.

It was not possible to see the compromised pin in prior inspections because its condition was shielded by other steel components at the pin’s location. Indeed, were it not for the current project’s sandblasting activities, the pin’s condition might not have been discovered.

The severity of the pin’s deterioration has been confirmed through ultrasonic testing, which indicated a problem with the pin’s structural integrity. (As a precaution, the bridge’s other lower- and upper-chord pins have been ultrasonically tested and all have been determined to be sound.)

Engineers have concluded that the compromised bridge span can remain in service in its present state, allowing a single lane of Pennsylvania-bound traffic and pedestrian traffic to use the current adjoining temporary walkway.

As an additional safety measure, the Commission has been strictly enforcing the bridge’s four-ton vehicle weight limit at the Lambertville approach through September. This stepped-up enforcement will continue throughout the fall. The critical pin-joint has also been outfitted with strain gauges to monitor stresses in the connection with the corroded pin.

Next Steps and Temporary Full Bridge Closures

The Commission is finalizing a two-step plan to bring vehicular traffic back onto the bridge in both directions and to reopen the new permanent walkway, which is nearing completion alongside the bridge’s downstream truss.

The first step involves designing, fabricating, delivering, and installing a customized device called a friction-collar system that would allow the compromised structural joint to function without risk of failure under heavy load.

If all goes according to plan, the friction collar could be installed over a two-week period later this fall, approximately around Thanksgiving. This installation is not anticipated to cause additional travel impacts; Pennsylvania-bound traffic can continue using the upstream lane, and pedestrians can use the adjoining temporary walkway while the device is installed.

However, activation of the device—a process known as post-tensioning—will require the bridge to close to all vehicles and pedestrians on two successive nights in early to mid-December. If this process proceeds as planned, the bridge’s new permanent walkway will then be opened to pedestrian traffic, and Pennsylvania-bound traffic will return to the upstream lane. However, the bridge will remain closed to New Jersey-bound traffic until sometime in early 2025.

The Commission anticipates it will be able to provide a firm schedule for the friction-collar installation process in November.

The second step involves the design, fabrication, delivery, and installation of a new steel pin and repairs to various structural members connected by that pin. This installation could begin once the friction collar is installed, but it will require an uninterrupted two-week closure of the bridge to all vehicular and pedestrian traffic. Rather than conduct this work immediately before the winter holidays, the Commission plans to schedule it for early 2025 to mitigate impacts to New Hope and Lambertville during the holiday season.

Details still need to be finalized, but the Commission expects to provide specific dates for the two-week bridge closure shortly after the start of the new year.

Impacts on Current Bridge Rehabilitation

The unforeseen structural issue with the critical joint in the bridge’s second span will delay the completion of the current rehabilitation project. At this time, it is anticipated that only alternating single-lane travel restrictions will be needed to complete any remaining construction tasks carried over into the new year.