Travel has gotten a little easier for motorists driving through Weston since the official opening Thursday, Oct. 29, of the new Route 57 bridge — also known as the Cobb’s Mill Bridge — over the west branch of the Saugatuck River. State officials, including Department of Transportation Commissioner James Redeker, presided at a ceremonial opening.

Work on the bridge began in early July and was supposed to have been completed Sept. 15, but the opening was delayed until yesterday.

At the opening, despite the delay, Redeker highlighted the DOT’s use of a new bridge replacement method to accelerate construction and reduce the cost of replacing the bridge. The DOT received a federal innovation grant for utilizing Bridge-in-a-Backpack, a technique that allows bridges to be built in weeks instead of months using fiber-reinforced polymer tubes so there is no need for heavy construction equipment, steel beams or freight trucks.

The original bridge, built in 1933, had been classified as “structurally deficient” and has an average of 9,100 vehicles crossing per day. According to the DOT, the bridge was successfully replaced in 16 weeks with a new arch structure consisting of prefabricated fiber reinforced polymer tubes with self-consolidating concrete, fiber-reinforced polymer decking panels, which forms the arch, and are covered with subbase material, pavement and cast-in-place moment slabs with barrier curb.  The composite shell provides a protective barrier that keeps out road salt, chemicals and moisture, which eventually penetrate and degrade conventional bridges.

Precast concrete block retaining walls were used at all four corners of the structure to help expedite construction. Additionally, the Route 57 roadway was widened to accommodate a 12-foot travel lane and five-foot shoulder/bike lane in each direction.

The “Bridge-in-a-Backpack” process was captured in a time-lapse video of the Route 57 replacement project.