Ok but that's still not adding up for me, maybe I'm missing something since I have looked at Metrolinx's blog. But the corridor was going to be widened and squared off/hardscaped regardless with RER or whatever we're calling it. And looking at Line 2 around Kipling or Line 3 parallel to Uxbridge Sub, there's a sizable gap between mainline and subway. Which is obviously some kind of mandated requirement. So with 6m between subway and mainline, is there room for all those tracks. Even 35yrs ago going above the corridor was the solution (of a rejected option).
I'm uncertain if any 'additional' separation distance is mandated;
@crs1026 and
@smallspy would be the people to know that.
I examined the corridor width, assuming 3.5M for each track; on that basis, the current embankment is clearly insufficient in most places.
With hardening and using the additional space from the outer limits, yes, it appears feasible, just, with bridges having to be widened for additional track.
Though there are some very tight spots, even then.
What I cannot reconcile is the platforms and egress options.
If, in fact, additional separation distance is required, all bets are off, particularly since the side alignment of O/L would mean 2 points of separation.