Lakeshore West Line GO Expansion

A business case is a report that is written to explain why a project should be built. It includes the benefits that a project would deliver, as well as potential risks. Metrolinx creates business cases for major projects to secure approval before moving on to detailed project studies, such as the Transit Project Assessment Process. Business cases provide evidence to decision-makers, stakeholders, and the public as a crucial part of transparent and evidence-based decision making processes.

An environmental project report, or EPR, is the final product of a Transit Project Assessment Process (TPAP). After the 30-day public and stakeholder review period is complete, Metrolinx prepares a final environmental project report and submits it to the Ministry of the Environment, Conservation and Parks for review. Once the final report is reviewed and approved, Metrolinx can then start detailed design, procurement and construction.

The Transit Project Assessment Process (TPAP) is the process created specifically for transit projects. It can also be referred to as an environmental assessment. This process includes a pre-consultation phase and then a phase of up to 120 days when the positive and negative impacts of a transit project are studied.

A key aspect of a TPAP is to make sure that the natural, social, cultural, and economic environments are protected and any potential negative impacts are either avoided, reduced or minimized. Throughout the process, Indigenous communities, the general public and stakeholders are consulted.

TPAPs are regulated by Ontario Regulation 231/08 from the Environmental Assessments Act. This regulation also allows Metrolinx to make changes to a transit project after the final Statement of Completion has been approved. This is done by preparing an addendum to the environmental project report. The addendum process looks at the impact the change might have on the environment. Then an addendum report is developed and shared, as well as an official Notice of Environmental Project Report Addendum. The public and stakeholders are then included in a final review of the addendum before it is included as part of the project.

Priority transit projects follow a different environmental assessment process. See our Ontario Line Studies page for more information.