City committee hears engineering study that points to full replacement of Rochester Neck Road bridge

The Public Works and Building Committee on July 17 heard a detailed engineering study on the Rochester Neck Road bridge that concluded the structure is nearing critical condition and that full replacement is the likely long-term solution.

The study’s lead presenter, Aaron Lachance, a senior structural engineer and vice president with Hoyle Tanner, told the committee the bridge—built in 1979 and last rehabilitated in 1999—is in “fair” condition but is “very close to being red listed.” He said inspectors rated the bridge overall 5 out of 9, with the superstructure rated a 5 and the substructure a 6, and noted the five steel girders were repurposed from an earlier project and may be older than the bridge itself.

The study matters because the bridge carries about 1,062 vehicles per day, roughly 13 percent of which are trucks, and serves regional traffic between Rochester and neighboring communities including Dover, Barrington and Madbury.

Engineers described the work done for the study: hands-on bridge inspection, geotechnical borings, traffic counts, origin–destination analysis,…