‘Widening this important corridor will reduce commute times, improve traffic flow, and support the continued growth of our communities,’ says MPP
The provincial government has awarded a detailed design contract to widen Highway 400 from six to 10 lanes between Highway 9 and the future Bradford Bypass.
Officials visited King City on Oct. 5 to announce the widening, which will be built north of King and Newmarket. The 11-kilometre section of the highway will have one general-purpose lane and one high-occupancy vehicle lane in each direction.
Minister of Transportation Prabmeet Sarkaria said the expansion stands to address gridlock and “keep our economy moving.”
“Advancing the widening of Highway 400 will help get drivers where they’re going faster, strengthen a critical trade corridor and keep people and goods moving in the Greater Toronto Area,” Sarkaria said in a news release.
American company AECOM has been awarded the contract to do the work. The province has been working for several years to expand different sections of Highway 400, completing a widening near Vaughan in 2025 and also planning to expand the road near Barrie.
Major construction on the Bradford Bypass (Highway 425) also began in May 2026.
The province said the contract will also include work related to culverts, signage, drainage, storm sewers, lighting and interchange ramps along the expected highway. The province said Highway 400 is a critical transportation corridor, moving billions in goods across Ontario and Canada.
“For families and commuters across York-Simcoe, Highway 400 is an essential part of getting to work, getting home, and staying connected to communities across the region,” York-Simcoe MPP Susan Lahey said in a news release. “Widening this important corridor will reduce commute times, improve traffic flow, and support the continued growth of our communities. I’m pleased to see our government is taking this important next step.”
Vaughan Chamber of Commerce vice-president of government affairs and strategic initiatives Abdus Samad said congestion on the highway means delayed shipments, higher costs, and longer commutes.
“This announcement is an important step toward strengthening a corridor our manufacturers, distributors and other employers rely on,” Samad said. “We welcome the province’s investment in the transportation capacity needed to support business growth and keep Ontario competitive.”
The provincial government said it is investing $31 billion to build, repair and expand highways, roads and bridges across Ontario.