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Network-Wide Structures Project

Network-Wide Structures Project

What's New?

The Environmental Project Report Addendum for the McNaughton Road Grade Separation (part of the Network Wide Structures Project) is now available for public review from June 4 to July 5, 2021.


As part of the GO Expansion Program, Metrolinx has identified various infrastructure required to achieve service level targets across the network.

This project represents a change that was not examined in the previously approved Barrie Rail Corridor Expansion Project Environmental Project Report (2017), and requires a Significant Addendum under the Transit Project Assessment Process (TPAP) (Ontario Regulation 231/08).

The purpose of the Project is to accommodate the expansion of the Barrie Rail Corridor through grade separating at-grade road-rail crossings. These improvements will enhance on-time performance, operational flexibility / reliability, and reduce traffic conflicts. The Project will facilitate the GO Expansion Program, including allowing for the construction of a previously approved new track. To support GO Expansion along the Barrie Rail Corridor, the following at-grade crossing will be altered:

City of Vaughan, York Region

As part of the Network-Wide Structures Project, Metrolinx has continually worked with the Town of Aurora, York Region and property owners to land on a design solution for the proposed grade separation at Wellington Street East. While progress has been made on multiple fronts, there is still work to be done to agree on a solution that meets the needs of the Town, Region, property owners and GO Expansion.

To account for the additional time needed for a design solution, Metrolinx will seek EA approval for the Wellington Street East Separation Project through a standalone addendum to the 2017 Barrie Rail Corridor Environmental Project Report (EPR). The EPR addendum will take place once work is complete to address the outstanding stakeholder concerns related to its design.

A map displaying the Barrie Rail Corridor from Wellington Street East to McNaughton Road.

Project Status

The Notice of Addendum for the McNaughton Road Grade Separation (part of the Network Wide Structures Project) was issued on June 3, 2021 and the 30-day public review of the Environmental Project Report (EPR) Addendum is underway from June 4 to July 5, 2021. 

Round 2 of public consultation for the McNaughton Road Grade Separation (part of the Network Wide Structures Project) was held online from November 27 to December 11, 2020.  Note this was Round 3 of public consultation for the full GO Expansion program. View the materials from this round of consultation. 

 A round of public consultation was held online from August 18 to September 1, 2020 for the Full GO Expansion program. Participants were able to read about the Network Wide Structures Project and ask Metrolinx general questions about the project. There was no new information from the Network Wide Structures Project presented in this round.Round 1 of consultation was held in person in February 2020 to introduce the Network Wide Structures Project.  View the materials from Round 1.

The Transit Project Assessment Process (TPAP) is a focused impact assessment created specifically for transit projects. The process involves a pre-consultation phase followed by a regulated up to 120-day phase and includes consultation, an assessment of positive and negative impacts, an assessment of measures to mitigate negative impacts and documentation.

A TPAP ensures that the natural, social, cultural, and economic environments are protected and any potential adverse effects from proposed infrastructure are either avoided, mitigated or minimized.

TPAPs are regulated by Ontario’s Environmental Assessment Act, specifically Ontario Regulation 231/08 - Transit Projects and Metrolinx Undertakings, and are submitted for the Minister of the Environment Conservation and Parks' review prior to completion.

Public, agency, and Indigenous consultation occurs throughout the process.

An EPR Addendum is carried out under Section 15 of Ontario Regulation 231/08 - Transit Projects and Metrolinx Undertakings, which includes provisions for proponents to make changes to a transit project after the TPAP Statement of Completion is submitted and approved.

If, after submitting a Statement of Completion, the proponent wishes to make a change to the transit project that is inconsistent with the environmental project report, the proponent shall prepare an addendum to the EPR. The following outline describes the key steps in the EPR Addendum process under the TPAP:

  • Prepare an assessment of the impacts the proposed change may have on the environment;

  • Prepare and distribute an Addendum report;

    Prepare and distribute a Notice of Environmental Project Report Addendum; and

  • Conduct a final review by the public and stakeholders prior to proceeding with the proposed Addendum.


All proposed new transit infrastructure as part of the GO Expansion program being assessed through the TPAP under Ontario Regulation 231/08 - Transit Projects and Metrolinx Undertakings, either as new TPAPs or as Addenda to previously completed and approved Environmental Assessments or TPAPs.

As part of the GO Expansion program, Metrolinx is increasing service on the Barrie Rail Corridor. System upgrades are being planned along this rail corridor, including the modifications of the infrastructure necessary to support the introduction of additional trains to meet these needs.

On October 5th, 2017, the Ministry of the Environment, Conservation and Parks (MECP) issued a Notice to Proceed to Metrolinx for the Barrie Rail Corridor Expansion Project. Subsequently, a Statement of Completion was submitted by Metrolinx to MECP that completed the TPAP. Through ongoing planning and technical studies completed as part of the Network Wide Structures Project, the McNaughton Road grade separation was proposed as a change along the Barrie Rail Corridor to enhance on-time performance, operational flexibility / reliability and reduce traffic conflicts.

This change (the proposed McNaughton Road grade separation) to the Barrie Rail Corridor Expansion Project was determined to be inconsistent with the project description outlined in the Barrie Rail Corridor Expansion Project Transit Project Assessment Process Environmental Project Report (BRCE EPR) (Hatch 2017a). As described in Section 15(1) of Ontario Regulation (O.Reg.) 231/08, any change that is inconsistent with a previously approved EPR requires a reassessment of the effects associated with the project, the identification of potentially new mitigation measures, and potentially new monitoring systems in an Addendum to the previously approved EPR. Therefore, Metrolinx has prepared this EPR Addendum to address the effects associated with the proposed McNaughton Road grade separation.

Metrolinx has now completed an EPR Addendum under Ontario Regulation (O.Reg.) 231/08, Transit Project and Metrolinx Undertakings for the Barrie Rail Corridor Expansion Project for the McNaughton Road grade separation. The TPAP was used to assess the potential environmental impacts associated with the transit project, identify mitigation measures for those impacts, and to develop a monitoring program to verify the effectiveness of the proposed mitigation measures.