Jim, I believe the speed limit on the MTC sub between Milwaukee Jct. (where the sub now begins) and Nolan is 30 MPH and 50 MPH from Nolan to Tappan.
I have heard that the plan is to eventually raise the speed to 60 between South Haven and Tappan - with some restrictions. 8 Mile, 7 Mile, Van Dyke, Davison and 6 Mile are the only grade crossings between Milwaukee Jct. and Nolan. South of 6 Mile the railroad is a bit inaccessible save for the Mt. Elliot overhead bridge between Forest Lawn and East Yard. Between Milwaukee and Delray (Shoreline sub), there is little access to the tracks. Can't, off hand, think of any remaining crossings at grade. Hope this helps.

RandallG