Project Location: Bridge 19 and 20 are located on VT 118 in the Town of Montgomery in Franklin County. Bridge 19 spans over the Trout River near the intersection of VT 118 and Comstock Bridge Road and Bridge 20 spans over West Hill Brook on VT 118 between West Hill Road and Hill West Road.

The Montgomery STP DECK(40) & STP DECK(47) project will replace the existing bridge decks, which have non-crash tested bridge and approach railing, with a new bridge deck that meets current design standards. The existing bridges are three span structures with concrete decks on rolled beams constructed in 1953. Bridge 19 is approximately 177 feet in length and 30 feet wide and Bridge 20 is approximately 127 feet in length and 30 feet wide. The existing bridge rails feature concrete parapets with tubular metal railing and a curb with “wind slots”. The bridge decks are in ‘poor’ condition while the superstructure and substructure are in ‘good’ and ‘satisfactory’ condition, respectively. VTrans bridge inspectors have observed areas of heavy saturation, cracking, and efflorescence in the decks which is evidence of significant concrete deterioration. The bridge is owned and maintained by the State of Vermont.

VTrans evaluated several alternatives to preserve and extend the service life of the bridge decks in an engineering study completed in February of 2016. The study assessed the proposed design criteria for lane and shoulder widths, safety criteria, and historic requirements. Several alternatives were considered including, no action, concrete deck patching, and deck replacement. The study also considered a number of traffic maintenance options such as a short term bridge closures and phased construction. The engineering study recommends replacing the existing bridge decks and bridge railing through phased construction (maintaining one way, alternating traffic while the bridge deck is replaced in the opposite lane). This method will minimize impacts to right-of-way, utilities, and the environment.

The new bridge decks will be constructed using conventional cast-in-place construction methods. The new bridge deck will be the same width, be continuous over the piers, and have a greater load carrying capacity than the existing decks. It will also feature a new crash tested bridge railing that ties into the surrounding community and satisfies the historic requirements. By applying this cost-effective treatment at the right time, the useful life of the structures will be extended another 30-40 years. This provides the largest benefit for the lowest cost when compared to the other bridge treatment alternatives.