Having trains that run through the entire map, while a neat overall concept, kinda falls apart when putting moving trains on them. Especially with no audio warnings and how often trains pass over them, it's honestly scary trying to cross (which is necessary to leave the last point or to leave mid).
If you want active trains, you should isolate them to an area where they'll cause less harm and they'll be more predictable, like how Well only uses them at mid (they don't cross super often, have an early and loud audio warning, and people still don't like them much). My personal recommendation is to eliminate the moving trains entirely and instead place stationary cars where they can provide nice high ground/cover.
The trains can push you into the wall while walking on the path.
This area seems like it wants to be a high ground, but there's an 80% chance you'll get stuck in it. Putting a cover over the top would make it a lot more usable.
You can (and likely will) get stuck in this little ditch. I can only assume that's intentional, but I don't recommend making players fight against the map.
This balcony has a direct sightline to the point. If you run a test on this map, I can almost guarantee that both teams will have 2-5 snipers. Not just because of this one sightline, either: Mid in general is VERY open to sniper fire because of how linear and tall it is, and the subway tunnels don't have any cover (sans the moving trains).
I think the overall layout makes some sense, but there's some ideas about scale and routing that don't quite work. Subway tunnels can make some interesting spaces, but I think you'll need to force players to take routes that make sense. For example, coming from mid attacking 2nd, using the subway as a route is
most likely going to lead you completely past it. The door in is hidden from view. Once inside, the route then seems to become
a cramped flanking route. It being a flank route isn't inherently bad, but from the outside it's the most obvious route -
the larger route in is kinda hidden and also far away.
Mid itself is a very strange design - the two upper routes are very linear, making them very vulnerable to sniper fire (not to mention kinda boring to play on), and you can't access them from the lower area at all. Actually being on the point is really undesirable because of not only how much high ground surrounds it, but also how much clutter there is in that area (lots of chairs/tables to get stuck on). I'd recommend clearing out the lower area of clutter and making the high ground much more sparse/not as close to the point/more accessible to everyone or only accessible to soldiers/demos/scouts. Look at how Process/Snakewater/Granary have high ground like this at their mids. The low ground should be the area most people want to go, but the trains and high ground make it really undesirable.
Opening all of the routes out of last into the same area will create choke issues - teams won't be able to flank each other, and positioning will hardly matter.
Railings in the middle of stairs might look nice (and fit the stair model) but they'll get in the way of players trying to play.
Health/ammo above mid are asymmetrical.
