The Delaware River Joint Toll Bridge Commission on Monday announced a series of off-peak and overnight travel restrictions scheduled to begin next week at the New Hope-Lambertville free bridge.
They say the restrictions are needed to allow engineers and consultants to assess different kinds of electronic sensors that could be used to evaluate the bridge’s long-term structural health and to “gain a better understanding of how overweight/oversized vehicles affect the agency’s aging weight-restricted crossings.”
The travel-restricted periods will affect motorists using the bridge in either direction, and are scheduled to be implemented at follows:
- Sept. 15 to Sept. 18 – daily from 9 a.m. to 11:30 a.m. and 1:30 p.m. to 3 p.m. – the bridge will be restricted to a single, alternating lane of traffic controlled by a flagger at each end. These closures, spread across four days, will allow for the installation of various bridge monitoring sensors on different sections of the bridge.
- Sept. 19 – early morning hours, 1 a.m. to 5 a.m. – intermittent traffic stoppages lasting up to 15 minutes will be used to allow for pilot tests of the installed monitoring devices.
Motorists planning to travel across the bridge during above-mentioned periods are advised to allow extra time to reach their destinations, said the Delaware River Joint Toll Bridge Commission. The travel restrictions are subject to change due to weather, emergency, and traffic considerations, and drivers should reduce their speeds whenever traveling through a designated work zone, they added.
The work at the bridge is being conducted as part of a Bridge Monitoring System Study for Select Vehicular Bridges Project that the Commission approved in May. The project will evaluate how sensor-type technologies could be used to assess the effects of heavy loads at some of the agency’s oldest bridges. Ultimately, the study could determine the feasibility of using sensors as a detection, enforcement and early-warning tool at the agency’s weight-restricted bridges.
The steel-truss superstructure between New Hope and Lambertville is considered a good testing ground for bridge monitoring sensors because of its age (the trusses turned 110 years old in July) and because the bridge experiences periodic overweight truck violations more frequently than many of the Commission other aging bridges.
The New Hope-Lambertville Bridge has had a four-ton weight restriction since 1971. This load rating was instituted because of its heavy traffic volumes – including large trucks – as the former river crossing point for U.S. Route 202 between 1935 and 1971. The bridge also sustained some structural damage during the ice flood of 1936 and the record-setting flood of 1955.
The core purpose of the Commission’s study is to gauge how “Structural Health Monitoring” (SHM) techniques can improve the safety and maintainability of the agency’s inventory of aging vehicular bridges.
SHM combines a variety of sensor technologies with embedded measurement controllers to capture, log and analyze how a bridge carries and distributes loads and how excessive loads affect a bridge’s structural integrity. Among other things, sensors can detect temperature, strain and displacement of steel members, and corrosion.
The study also is expected to provide insight on how sensor-based monitoring could enhance the commission’s ability to detect and deter overweight/oversized vehicles as a means of better enforcing weight limits at the agency’s aging vehicular crossings. The superstructures at six of the Commission’s non-toll bridges are now 100 years old or older.