^ I'm not even sure what we're debating anymore in terms of timing or what point your trying to make. That said, I'll correct my record above. It was in fact May 2019 is when Metrolinx said there were four options for the Bowmanville Extension. It wasn't until December 2019 at a townhall they said they reached an agreement with CP Rail for the option to use the GM Spur bridge over the 401, which was an indication on which of the four options they were going with. Video here timemarked to the specific comment:
The IBC then came out in February 2020 confirming the option chosen.
So, a few factors. The new GO/VIA station was designed to allow for an extension and the bridge piece to be added as
@crs1026 mentioned above. That was well before the "four option" discussion or the TPAP. I'm just saying whatever team worked on the Bowmanville Extension and the TPAP (may have even been the same team), would have be aware of future options for the extension. In my view, it looks like a side benefit of the TPAP design for Oshawa is that it could benefit/assist with the Bowmanville Extension. Great.
The drawings you provided from the past are helpful for context, the most recent drawings I posted that became public in the last few days provide a more zoomed in view, which is great. The next step for the Bowmanville Extension, assuming funding continues for it, is more detailed design and public drawings, which I assume we will see well before five years from now.
I just checked the GO Bowmanville Extension document page and there was a September 2020 notice that investigation work is happening.
"What Work is Taking Place?
Along the CP-owned corridor there will be geo-technical investigative work underway beginning in September. This work is to collect information for the future Bowmanville Extension Project between Oshawa GO Station and Regional Road #57 in Bowmanville. The geo-technical work is necessary preliminary works in advance of Bowmanville Expansion construction. This work will be ongoing for a few months."
In looking at the map provided and how close the Thornton's Corner East Station is to the existing Oshawa Station, maybe the Bowmanville Extension trains won't stop at Oshawa and the trains will just pass by the new platform on the north side. I haven't looked at the IBC lately to remember if it has any service details for the GM spur option.
So one would hope there would be more details in 2021 on the Bowmanville Extension progress. Given the political pressure in Durham for the Extension, I don't think it will take five years to get more news or have a conversation about any changes/track expansion at the Oshawa GO Station.