Building on the recommendations of the Bowmanville Expansion Initial Business Case (IBC) approved at the February 2020 Metrolinx Board meeting, the Preliminary Design Business Case confirms the feasibility of the alignment identified in the IBC, while examining two different weekend service options. The alignment proposes one new track plus sidings and passing tracks where necessary through Oshawa GO station connecting to CP’s GM spur line to cross Highway 401, making an eventual connection through CP’s Belleville Subdivision to Bowmanville. When service opens in 2024, the line will provide four morning trips along the line to Union Station in downtown Toronto, and four afternoon trips making all station stops to the new Bowmanville station. In September 2021, geotechnical work began along the Canadian Pacific-owned part of the rail corridor that eventually will lead to an expanded GO Transit line all the way to Bowmanville.