[M1EK]

We know there isn't enough room for 2 commuter rail tracks + 1 urban rail track (much less the 2 urban rail tracks that would seem to be required) because CM has already told us there isn't even enough room for 2 commuter rail tracks + rails-with-trails in some parts of this corridor which despite your claim is nowhere near as wide as DART's in the part of the corridor where SAM was proposing running urban rail vehicles. Talking about how you can fit N tracks in some corridors is spectacularly unhelpful here. Obviously that's true; there's rail corridors in parts of the country with dozens of tracks in them.

Perhaps in the future you should argue specifics rather then generalities in this topic?