Highway 406 Expansion

IBI Group provided oversight for the detail design of the Highway 406 twinning from Port Robinson to East Main Street, including:

• 6 km of new 2 lane highway
• Realignment and rehabilitation of some sections
• Grade separation and interchanges
• Multi-lane roundabout
• 7 additional bridges
• Traffic signals and full illumination
• Storm water management

A major component of this project was the design of the bridge crossing the old Welland Canal, Merritt Island and the Welland River. This required the detail design of 11-span prestressed CPCI 1400 girder curved bridge carrying two lanes of northbound traffic. Reinforced concrete piers were fully submerged into the Welland Canal with piles extending below the canal bed.

IBI consulted various Ministry offices as well as Niagara Region, City of Welland, Town of Thorold and emergency service providers throughout the design process. The roundabout was subjected to a driver simulation study, human factors review, cost risk assessment study, and public consultation.

Highway 406 acts as the primary north-south route through the central portion of the Niagara Peninsula and the expansion required multi-stage construction to ensure an acceptable level of service could be maintained for motorists.

Construction staging and scheduling was complicated by consolidation requirements of the underlying soils in high fill areas throughout the project. The project also included several sensitive environmental issues including addressing new Species at Risk legislation in dealing with Mapleleaf Mussels found in the Welland River, Pin Oak transplanting as compensation for loss of provincially sensitive wetland and a number of enhancements to compensate for loss of fish habitat.