plans for Highway 406 called for this section to follow the creek valley the full distance to the QEW, interchanging with it east of Martindale Road. Instead, the alignment was moved west of the city. Realignments to several streets in St. Catharines were completed in advance of construction on overpasses, ramps and the bridges over Twelve Mile Creek; this work was finished in late 1983. Grading contracts were awarded in mid-1983 for the entire extension. Paving took place during the summer of 1984, and the route was opened to traffic in October 1984. Further work to extend the future southbound lanes Highway 406 to East Main Street in Welland began during the fall of 1987, including an eastward extension of Woodlawn Road. Construction of the bridges that carry the extension over the Welland River and old canal began in mid-1988, and was completed during the fall of 1989. Work then began to grade and pave the Woodlawn Road Extension to Highway 406 and Highway 406 between there and East Main Street. The extension was completed by the mid-1990s. Expansion Highway 406 was the last 400-series highway that featured at-grade intersections and two lane sections. The original intention was to twin this two-lane section shortly after it was constructed in the 1970s. Plans were deferred multiple times, until the project resumed in the early 2000s. The first phase of this twinning opened to traffic in 2007, extending the four-lane highway from its previous convergence south of Beaverdams Road to a point north of Port Robinson Road. On May 15 2009, Minister of Transportation Jim Bradley announced that the section from Port Robinson road to East Main Street in Welland would be converted to a full freeway; this work included a roundabout at East Main Street to replace the existing signalized intersection. Work on the Merritt Road overpass began in September 2009, and was scheduled for completion in mid-2011. On August 19, 2011, full construction began with a groundbreaking ceremony. The roundabout with East Main Street opened to traffic on September 5, 2013, featuring no central island. By September 2015, all the at-grade intersections had been removed and the 406 was a minimum four-lane, controlled-access freeway for its entire length. Despite requests from local politicians, there are no plans to extend Highway 406 to Port Colborne at this time. Exit list References External links Highway 406 images @ AsphaltPlanet.ca Highway 406 expansion