I think the HSR train that operates in this section will be an Ontario/Metrolinx HSR train at first.As for VIA HSR potentially having a conflict with UPX, I don't think that'll be much of an issue. VIA trains would be stopping at Malton (North Hub) just before the UPX spur joins the mainline. Timing could be worked out so that a VIA HSR train
Ontario Metrolinx is out-spending Federal VIA on rail by more than an order of magnitude -- tens of billions over the next 10 years (on GO and LRTs)! Metrolinx owns the track that goes by Pearson, and most of the way to Kitchener. With the Ontario Liberals talk of $10 high speed commuter train fares, HSR is essentially GOTrain RER II Sequel. This may become a new Metrolinx subsidary (much like Presto and UPX). But both VIA and Metrolinx HSR trains can share the same corridor, much like in Europe that domestic TGV/international Eurostar high speed trains, share the same HSR corridor. For example, theoretically the GO Express trains (from Kitchener) may be replaced with HSR trainsets as part of a RER Phase II past the current 10-year plan, if Ontario had its way. Coincidentially, the end of service life for current Bombardier Bilevels puts many of the coaches squarely into the 2030-2040 timeframe, perfect timing for HSR introduction -- high speed GO trains as RER II. Probably not under the GO brand name, but it might as well be. Most people on France/Japan HSR trains during peak hour are daily work commuters! And existing TGV/Shinkansen high speed trains on some routes go as frequent as 5-10-15 minutes AD2W!
The whole London-Kitchener-Perason-Toronto-Oshawa-Kingston becomes a daily commute when all of that is just 1 hour from downtown Toronto. There are many thousands of TGV/Shinkansen commuters that commute 100-200km one way daily (200-400km roundtrip), and this is a primary market of filling 15-minute-frequency high speed trains chock full to capacity, and this is Metrolinx's ballgame. TGV high speed trains came first in France, long before Eurostar international high speed trains went over TGV routes. Metrolinx owns the track that VIA high speed trains would need to go over, and the biggest market for high speed trains is the ~$10 daily commuter market.
Politics do change, so VIA may actually end up coming first, but this isn't what is happening now. Ontario has put money in the high speed train pot -- including few million dollars towards a comprehensive EA for high speed trains. Separately, Ontario has allocated funding for GO RER electrification of over 100 kilometers of what will be the future high speed train route (Oshawa through Bramalea). This is fully congruent to future high speed train service. There are long-term plans to electrify all the way to Kitchener fully 100% on Ontario's dime. That results in nearly 200 kilometers of electrification of the corridor for HSR trains. As a result, ownership of the rail and electrification means that Ontario de-facto fully owns a large amount of our upcoming HSR-compatible infrastructure.
The thorny question is who will be first with HSR? The answer is currently obvious: Follow the money. And know the precedent of high speed trains is the commuter market in other countries. You strongly smell an Ontario-operated (possibly Metrolinx) high speed train is going to be involved, whether VIA also operates or not. Both commuter and long-distance high speed trains will likely exist, and the question boils down -- who operates the commuter HSR trains and who operates the long distance HSR trains?
It is bad politics for Federal to play Favourite to Ontario and generously operate high speed trains for Ontario. BC and Alberta will yell blasphemy if they don't get quid pro quo funding -- so Federal is just going to let Ontario start a commuter high speed train, and Ontario's GO spending expansion, if maintained past 10-year timeline, is big enough to result in a HSR train within 20 years. Once Ontario paves the way with starter HSR, Federal will jump in to pull more rail towards Quebec/Windsor (while funding other initiatives like Calgary-Edmonton).
Both Metrolinx and VIA probably will co-operate on HSR. It is is easy to speculate that both will definitely run highspeed trains if our tracks become high speed compatible. Further discussion can be found via searching the HSR thread.
We are impatient, yes -- but on the positive side -- whatever we fund towards AD2W is a BIG step towards Pearson Rail Hub. The electrification of RER to Bramalea, brings catenary that's already automatically compatible with high speed trainsets, SmartTrack and/or GO RER, since the same infrastructure brings more trains at higher frequencies to whatever station we deem to be the main Pearson interchange station. Then that station is slowly expanded to Pearson Rail Hub.And - before we distract ourselves with too many good brainstormed new ideas that all need funding - can we please get on with plain vanilla 2WAD GO service to Brampton, as was supposed to have happened all along???? Just call it STRERGO and everyone will feel they get the credit.
So rewording the question, which station should become the Pearson RER station to interchange with the existing UPX for now? That station might end up becoming the future Pearson Rail Hub, on an incremental basis.