Abstract Manager

In 2008, the Ontario Ministry of Transportation (MTO) initiated a Phase 1 EA study to identify a transportation corridor linking growth centres in the north-west quadrant of the Greater Toronto Area (GTA). The study recommended a new corridor consisting of Highway 413, a 10-lane freeway with an adjacent transitway between the existing Highway 401/407ETR interchange in Halton Region connecting to Highway 400 in York Region. This proposed 55km corridor would require the construction of four new system interchanges. The biggest technical challenge of the study was to confirm feasibility of connecting Highway 413 to the existing Highway 401/407ETR interchange, and to provide directional ramp connections to and from each freeway. To confirm feasibility, three alternatives were developed. 

In 2014, MTO initiated Phase 2 of the study to complete the Preliminary Design and EA for Highway 413, including the new five-leg system interchange at Highway 401/407ETR. Key constraints included fitting a new unplanned freeway connection to an existing system interchange. Major arterial interchanges located east, west and south of the proposed connection further complicated placement of ramps and speed change lanes. Finally, a municipal roadway that must be maintained also crosses though the existing interchange.

Alternatives for a transitway alignment connection through the four-level system interchange were identified, including a connection to the planned 407ETR transitway. Mid-way through the study, the design speed was increased from 120km/h to 130km/h requiring modifications to the interchange. A Value Engineering study for the broader Highway 413 project was conducted in May 2024.  Several creative ideas were submitted to improve the geometry of the 401/407ETR/413 interchange, including replacement of proposed direct ramp connections with a 900m oval shaped rotary.  

The interchange was designed using TAC standards along with the MTO Design Supplement. Design exceptions have been documented in the Design Criteria. The preferred four-level interchange can be accommodated by maintaining all but one of the existing bridges. A review of the complex staging confirmed that no long-term ramp closures would be needed.  

The interchange design reached 90% completion in January 2025, with 100% completion scheduled for Fall 2025. The Highway 413 project has been identified as a priority project for the province and is anticipated to move into the next phase of design and construction in 2026.