Asking for some help with a (to be) transit-enabled model

[Francis90b 748]

Greetings from a newbie (in modding and transit networks, not in ST !).

I am working on a model of a tunnel entrance that should be functional and work as a road-subway transition piece.

I am still just working on the model, but i need to ask some infos that could help me in planning my future steps.

(Zoom 4 previews, 13x4 tiles footprint)

I'd like to ask a list of questions.

1)Could a lot be transit-enable for every road network, i mean, could it be transit enabled for maxis roads only or also for road types available in RHW and NWM? Knowing this would allow me to know which kind of roads can enter into the lot.

2)Which of those road types that can be converted into subway? Knowing this will help me in narrowing down the selection.

3)Among all the road networks that remains after question 1 and 2, would you please tell me which one is the one with the highest capacity? I'd like to use it if possible (see question 4 as well)

4) And if I link a subway with a road network, which one will determine the structure's capacity?

If, for example, the subway has less capacity than the road network i'm linking it to, should i be worried?

5)This is just an aestethic concern.

The tunnel (as i've designed it) would allow for a road whose maximum widht is of 11-11,2 mtrs.

IRL that widhth might even allow for a three lane road, but in SC4 roads and lanes are usually wider.

Among the road networks that remained avaliable after questions 1-4, which ones can fit into the 11 mtrs limit?

Which ones can fit into it with some work (e.g if i narrow or enlarge a bit the road before it enters the tunnel)?

Which ones wouldn't look good anyway?

Thanks for your time .