Dimensions - September/October 2008 - 5

Turning Design Around Construction continues to transform a three-mile segment of Route 7, a commercial thoroughfare in Wilton, Connecticut. Wilton is located in western Connecticut and was incorporated in 1802, with area historical records dating back to 1640. “Congestion issues necessitated this expansion,” says Thomas Harley, PE, manager of consultant design for the Connecticut Department of Transportation (ConnDOT). “We had originally considered the option of a limited access roadway, but following the NEPA [National Environmental Policy Act] process and after community discussions, determined the current approach would best serve the community.” Widening the road from two to four lanes is also intended to improve safety, as multiple dedicated turn lanes have been placed at key intersections. Addressing Sensitivities ConnDOT contracted with Dewberry to design the capacity improvements, including multiple bridge designs: widening the Route 33 bridge over the Norwalk River and Metro-North Railroad, widening the Route 7 bridge over the railroad, and replacing the Route 7 bridge over the Norwalk River. The design also involved extending a twin box culvert carrying the Goetzen Brook under Route 7. The designs required preparation of environmental assessments and construction staging plans that would mitigate potential effects on adjacent sensitive wetlands, as well as maintain drainage to prevent flooding. Route 7 Capacity Improvements Require Speed and Innovation Carefully staged construction on the Route 7 bridge has helped maintain traffic flow and prevent flooding or adverse environmental impacts. In securing the project right-of-way, ConnDOT representatives also worked with the local historic society to relocate several historic buildings to new locations within Wilton. Construction Sequence Innovation Maintaining access during construction to properties, local roads, and Metro-North’s busy Wilton train station were priorities for the community and ConnDOT. Dewberry developed sequencing plans that included a special low profile concrete barrier curb. Developed by Texas A&M University, the low profile barrier is only 28 inches high and has tapered ends, allowing the contractor to maximize the work zone while providing openings at driveways. Accommodating a Quick Change During construction ConnDOT representatives have also been working with Northeast Utilities to install a new power line. “In lieu of overhead lines, the utilities are being installed underground to respond to sensitivities in the community,” says Harley. “Accommodating the 345kilovolt power line is quite a strain on space.” Dewberry worked with ConnDOT and the construction team to facilitate a design solution where the utilities share the same right-ofway as the storm drainage pipes. Used for the first time in the state of Connecticut, the low profile barrier curb is helping drivers access the roadway with increased visibility. “We have been pleased with the Dewberry team’s design and responsiveness,” concludes Harley. “The utility construction came late in the game, and they were able to help keep things moving.” 5

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Dimensions - September/October 2008

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