In NYC we have 25mph speed limit, which succeeded in getting fatalities to zero city-wide, for a while. If big, planted median and sidewalk margins were added... and you could diplomatically get it down to two lanes, with heavily marked crosswalks mid-block (only for a short distance) with clarity on who has right-of-way - you could turn it into a more pedestrian-friendly area - which Corktown SHOULD BE - since it's historic, recreational, etc.
Hi Aaron: I have a partially designed 1.8mi subway line that might meet with your approval. There's not much unconventional about it though it might want to adopt a London Underground-type vertical squeezing to some extent: https://challenges.cityoftomorrow.com/challenge/detroit/explore/michigan-avenue-subway - The Grand Trunk 3-track elevated line in Detroit would do well to fill in with passenger service where this two-line spoke-and-hub subway doesn't go - probably for a higher fare - extending to Mt Clemons, Port Huron or... Toronto - since that route is way more advantageous in terms of population and could be made about the same length given revival of an old stretch in Canada. The Toronto approach is more populous too. Without something along the general route of this subway having reasonable speed and high capacity the prospect of reviving Michigan Central as a transit hub doesn't seem very likely - including another longer service I have in mind - Detroit-DWT-Downtown Toledo. (Terrible # of grade crossings on that one.)
Thanks again, that IS interesting and did a search coming up with several more reports at the Hathi Trust website. Going by the 1926 commission report the initial construction called for 46.6 miles of double-track subway lines at $187,789,000 - all in one blow - which is amazingly ambitious and (not knowing much about it but)probably why nothing ever got built. This followed a city-wide vote a few years earlier in which some huge majority was FOR it, with a plan that called for fares covering something like 33% of the cost. (I didn't get into the particulars.) The Commission had somehow been elevated within the legal framework commanding more authority by that time.
Surprising to me is that in the 1926 plan Michigan Central wasn't served directly - with a station out under Michigan Avenue, which, without the as yet un-invented conveyor belt people mover, would have been a non-starter as far as most of us are concerned I think. I distinctly recall finding some kind of gratifying proof there was a plan to go right up to the station, with an option to continue under the bridge... which with the current plan would extend it to Mexicantown - or better Livernois Avenue as long as your going to the trouble of getting over Interstate 96 - which is a bit more complicated and lengthy than the M-10. Spent quite a while sketching that out with realignments of several things necessary, and will try and dig it up, but that stage is a few past the 2nd and 3rd - with the extension north from the central hub being 1st and most important to enable storage and maintenance capacity sufficient for expansion period. (which might include an at-grade extension to Belle Isle provided the bridge would support it and traffic would not be too negatively affected by tracks and adequate barriers in the middle - or build a new bridge. I suppose it could be done with a single track and a loop at the end, as traffic on an island extension would likely be mostly sparse during the week. A short-train shuttle might be best since grade separation would have to commence in the middle of the bridge approach on the island (which broadens there) in order to achieve a loop station just past it. Something like that might be well liked but is peripheral/optional vs. the two (or four) initial stages - as is the Mexicantown one though maybe not. ((I heard it's up-and-coming. And a single-track bridge on an otherwise-two-track line might be a practicable option.))
The (subway) station tracks (two) at Michigan Central (see picture) would best be as close to the surface as possible, to avoid interfering with the foundations of the bridge, which go quite deep. There was difficulty initially, and a very sturdy steel-columned arrangement of a certain extreme depth was finally built. It's owned by CP now and is succumbing gradually to the elements - and I am inclined toward the idea of reversing the customary eminent domain thing of railroads and using it against them, because their stewardship of their properties (a lot of which were land grants after all) has not been exactly stellar. Michigan Central, St. Louis, Cincinnati, Buffalo - all these fantastic stations are victims of an MO involving selling off properties crucial to the business while collecting exorbitantly on an individual basis - thereby laying it lame - while constantly pleading poverty. The railroads did not lose their US Mail contracts and passenger business because the automobile and airplane became successful - it was because they wanted it that way. Every industrialized country except the US moves their mail largely by rail - so much for the rail-oriented postal palaces of the 20th Century, most of which are now permanently blocked. (So much for reasonable carbon footprints as well I suppose.) I live in NY and in my lifetime there have been three credible attempts to demolish Grand Central that I know of. They will eventually do it if not prevented. It's one of our greatest buildings - what else? the Capital? a few things by Wright? Historic preservation laws have no effect on these things whatsoever as long as they're privately owned.
Anyway, the two tracks of the Michigan Central subway station would be close to the surface as possible, involving a tunnel beneath the platform to reach the carriage entrance of the train station, and the necessary vertical amenities to to enable it. With a 50' platform (owing to config. of the bridge supports) some very pleasing options for the said amenities present themselves. The carriage entrance is stunning in its own right: (https://i.pinimg.com/originals/04/9f/70/049f70880cd5070b0b721cb4117cc2cb.jpg) As a partially glass-enclosed subway-oriented lobby giving onto the concourse - with possibly-diagonal stair/escalator bank - under the high, steel-gable ceiling with lanterns - it could be more so.