Project Location: Town of Westminster in Windham County on Interstate 91 over The Saxtons River and Saxtons River Rd (VT 121) . The bridges are located approximately 2.4 miles north of exit 5 along Interstate 91 (I-91). 

The Westminster I-91 Bridges 21 North and South were built in 1963 and consist of 7 and 8 span cast-in-place decks on rolled steel beams.  The 35 foot wide bridge structures are 534-feet and 542-feet in length, respectively. This project will replace the existing decks and repair the piers and pier caps. 

The existing bridges have a substandard width, approach rail and bridge railing. All these conditions will be addressed by the project. The superstructure beams are in good condition, but the concrete deck components are only in fair condition.   The substructures are in fair to poor condition, as a result of the deteriorated deck sections above, which allow water and salt to seep onto the bridge seats, damaging the pier caps. 

VTrans evaluated alternatives for rehabilitation of Westminster I-91 Bridges 21 N&S in an engineering study completed in October 2014.  The study assessed the proposed design criteria for the bridge and roadway alignment, right-of-way impacts, hydraulics and wetland and archaeological resources.  Several alternatives were considered including no action, repair and rehabilitation, deck replacement, superstructure replacement and full bridge replacement. Because of the structure’s age and condition, the study recommended a deck replacement with phased construction.  

Both bridge decks will be completely removed and replaced, as will the substandard bridge and approach rails.   Deck joints will be replaced to provide additional protection to the steel support beams. Deteriorated and loose concrete on the piers will be removed and repaired. The steel superstructure will be repainted in coordination with the deck repairs, since this work is due and will be more cost effective, if coordinated.

A new electrical protection system will be installed to slow future concrete and reinforcing steel deterioration, triggered by deicing salts and moisture. The new decks will be the same length as the existing ones, but will be widened slightly on each side, resulting in two 4’-8” wide shoulders and two 12-foot travel lanes for each bridge. The new decks will feature F-shape concrete bridge rail with Heavy Duty Steel Beam approach rails.

The bridges will be reconstructed in several phases using crossovers, which will transition both directions of traffic on to one bridge, so that the other bridge may be more safely repaired and upgraded.  Saxton River road (VT Route 121) traffic will be reduced to one lane using flaggers, as needed, during specific construction activities. Temporary traffic signals may be used for longer duration lane closures under the I-91 bridges.