Plans are underway to expand Hwy. 401 through Milton, as the province moves to ease congestion and prepare one of the region’s busiest corridors for future growth.
A 17-kilometre stretch between Steeles Avenue and the Halton-Wellington boundary is under review, with options that include widening the highway from six lanes to up to 10 lanes (including HOV) and improving carpool lots. The project is also expected to include replacing the First Line Nassagaweya bridge and upgrades to the Guelph Line interchange.
Traffic studies presented by the Ministry of Transportation at a council meeting this week showed the corridor already faces unstable traffic flow at peak times, with a near-constant gridlock expected by 2041 if no improvements are made.
Consultant Tim Sorochinsky described the stretch as “a missing link” that will connect recent and ongoing 401 expansions to the east and west of Milton.
The plans outline several options for widening, including expanding evenly on both sides of the highway or primarily to the north or south. Replacement of the First Line Nassagaweya bridge is expected, with several alignment options to maintain traffic during construction. Multiple reconfiguration options are also being considered for the Guelph Line interchange to improve traffic flow while addressing constraints like nearby wetlands and the Campbellville community.
Fourteen environmental studies are underway, covering noise, wildlife habitat and cultural heritage. Public consultation on preferred designs is planned for early 2026.
