The Regional Municipality Of York


Major Mackenzie Drive: Highway 400 to Highway 50

Transforming Major Mackenzie Drive

Section 3, proposed rendering shows how the intersection and bridge will align with the future Major Mackenzie Drive.

The Regional Municipality of York is investing in building a safe, efficient and reliable Regional transportation network for all users. Improvements to Major Mackenzie Drive from Highway 50 to Highway 400 in the City of Vaughan are underway to accommodate growth, improve traffic flow and provide public transit connections and more travel options for all.

Graphic map showing road construction area highlighting the four sections on Major Mackenzie Drive. For a detailed description of this map please call 1 877 464 9675 extension 75923.

Improvements include:

  • Widening Major Mackenzie Drive to six lanes
  • Providing a connection to the proposed Highway 427 extension
  • Realigning a portion of Major Mackenzie Drive between the Canadian Pacific Railway tracks and Highway 27 to provide a continuous connection across Highway 27
  • Building new bridges including a 150-metre bridge over the Humber River and a bridge over the existing level crossing of the Canadian Pacific Railway tracks
  • Installing multi-use paths, sidewalks and street lighting
  • Replacing old culverts with larger structures
  • Improving intersection accessibility
  • Installing wildlife fencing and wildlife culverts between Islington Avenue and Pine Valley Drive

Construction Update

Section 1: Pine Valley Drive to Highway 400

  • Construction is complete

Section 2: Islington Avenue to Pine Valley Drive

  • Construction is underway and is anticipated to be completed by fall 2021. During the first stage of construction traffic will continue to use the existing lanes, as construction will commence south of the existing roadway.  In the coming months you will see:

    • Tree clearing, topsoil removal and roadway excavation

    • Installation of traffic control barriers and temporary fencing

    • Bridge construction at the East Humber River and Purpleville Creek

    • Installation of wildlife culverts

  • Major Mackenzie Drive will remain open to traffic during construction and access to Islington Avenue and Pine Valley Drive will be maintained; however, temporary lane closures may be required between 9:30 a.m. and 3:30 p.m. for construction.

Section 3: Canadian Pacific Railway tracks to Islington Avenue

  • The majority of road work between Highway 27 and Islington Avenue is scheduled to be completed this year. A water main is being installed on the south side, which will be located under the future south boulevard.
  • Humber River bridge construction is well underway. To allow for the river’s flood waters to pass underneath the bridge, the bridge is higher than the existing road intersection at Major Mackenzie Drive and Highway 27. As such, the intersection will be raised this summer to match the level of the bridge.
  • To build the bridge over the Canadian Pacific Railway tracks, traffic has shifted to a temporary Major Mackenzie Drive detour and will be in place for at least two years. Large amounts of soil are being trucked in and placed to build the road leading up to the bridge on either side. This work is scheduled to take approximately four months to complete. Once in place, there could be up to a year of inactivity at this location as the ground underneath settles.
  •  Construction is scheduled to be completed in 2021

The bridge over the Humber River started to take shape this winter (Photo credit: DECAST)

With the girders in place, the Humber River bridge deck can be constructed this spring.

Section 4: Highway 50 to Highway 427 extension

  • Design is underway and utility relocation will commence later this year
  • Construction is expected to begin by the end of 2019 and is scheduled to be completed in 2020

Motorists may experience short periodic stoppages or lane closures due to construction. York Region recognizes this can be disruptive and will make every effort to minimize disruptions. Thank you for your ongoing patience.

To help manage your daily commute during construction, please plan your route in advance by using Waze, a community-based traffic and navigation app with real-time traffic and road information.


For everyone’s safety, please reduce your speed through the construction area. Please contact us if you notice any safety issues in and around the construction sites.

Transit services

For inquiries about transit routes during construction, riders are encouraged to visit or call 1-866-MOVE-YRT (668-3978).


Take a look at the Humber River bridge construction from a bird’s-eye view

We’re here to answer your questions. Accessible formats of this newsletter or communication supports are available upon request.


General Inquiries:
Vanessa Savelli
Communications and Community Engagement Specialist
Phone: 1-877-464-9675 ext. 75923

Construction Activity:
Gary Leonard
Construction Administrator
Phone: 1-877-464-9675 ext. 75233

After hours emergency: 1-877-464-9675 ext. 75200


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View Major Mackenzie Drive road improvements photo gallery


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