CDL.TO
Moderator
This is the option Metrolinx selected for future study:
You may be thinking of City of Toronto's maps, which is running its own studies, though only one or two of those shows a Western arm.
That's the Metrolinx option from ONE study, focussed specifically on relieving Union Station. Other Metrolinx documents have referred to the Dundas West alignment (such as the one that insertnamehere posted), and others say that the final routing is to be determined (such as the Technical Update).
That map is hardly final. It will undoubtedly feed into further studies, but isn't the official Metrolinx plans by any measure.