Improving Traffic Flow and Enhancing Safety for All Travel Modes on Route 18

Tetra Tech designed and permitted major improvements to a nearly five-mile section of Route 18 to relieve congestion and improve access and safety.

Tetra Tech helped the Massachusetts Department of Transportation (MassDOT) address safety issues and environmental concerns and improve local and regional traffic conditions associated with the redevelopment of the former 1,450-acre South Weymouth Naval Air Station. We assessed the environmental impacts and successfully secured environmental approvals, as well as completed the infrastructure design for major improvements to a nearly five-mile section of Route 18 in Weymouth and Abington, Massachusetts.

Our team met the project goals with a thoughtful design that included widening Route 18 from two travel lanes to four, intersection improvements, traffic signal upgrades, improved access, and new pedestrian and bicycle accommodations. Our environmental impact mitigation measures included noise wall investigations, stormwater management, wetland creation and restoration, and retaining walls.

Tetra Tech also developed detailed construction staging plans in coordination with the roll in of a bridge structure fabricated offsite to elevate Route 18 over an active Massachusetts Bay Transportation Authority commuter rail. We also prepared a joint National Environmental Policy Act environmental assessment and Massachusetts Environmental Policy Act environmental impact report, performed a wetland resource area investigation, successfully secured a Wetlands Protection Act variance from the Massachusetts Department of Environmental Protection and approvals from the U.S. Army Corps of Engineers.

Photo courtesy of MassDOT Fixed Site camera