In 2017, the Town of Innisfil completed a Schedule 'C' Municipal Class Environmental Assessment (EA) for the proposed interchange at 6th Line and Highway 400. The study:

  • Confirmed the need and justification for the project
  • Documented existing environmental conditions
  • Examined alternatives
  • Defined the preliminary interchange design

An Environmental Study Report (ESR) and Study Design Report were prepared to document the process, consultations, and recommended solutions.

Study notices

View the study notices and open house exhibits associated with the project:

EA Review and Study Update

In 2023, the Town entered into a co-proponency with the Ontario Ministry of Transportation to complete a Municipal Class EA Review of the preliminary design for the new interchange. 

This review identified several issues that suggested design changes for the proposed intersection were needed. A Study Update was prepared to outline these findings and proposed changes, which include:

  • Updating the interchange design to meet current engineering standards and best practices
  • Realigning the proposed interchange ramps
  • Replacing the previously proposed roundabouts at the ramp terminals with traffic signals
  • Replacing the existing Innisfil Creek culvert under Highway 400 with new bridges
  • Constructing new bridges over Innisfil Creek for the future West-to-South and South-to-East/West ramps

Community members had the opportunity to provide feedback on the Study Update and Preferred Interchange Plans by July 19, 2024.

Study notices

ESR Addendum and Review Period

An Addendum to the Environmental Study Report has been prepared to document the design changes identified through the EA Review and Study Update. 

The Addendum is available for review at Highway400-6thLine.ca. 

The public is invited to submit comments during a 30-day review period from August 13 to September 12, 2025. Please visit the project website or see the Notice of ESR Addendum for details on how to share feedback.