As for the turboshafts, it's an tnteresting layout, however I think it needs a little more in terms of redundancy and alternate routes, keeping in mind there could be, say a dozen or so cars whizzing about the place at any one time. Just to avoid bottlenecking as much as possible without ending up with more turboshafts than corridors. A tricky balancing act to be sure.
Also, I wonder if there shouldn't be a place for spare turbo cars to park off the main network, like the odd alcove or lay-by so if two cars are going in opposite directions down the same stretch, one can wait for the other to pass. There may even be a workshop where they go in for maintenance, somewhere in the secondary hull I imagine.
Ummm... Wow. This is a joke, right?
Even unfinished, with three complete loops and (for the few semi-complete decks of the primary hull) 20 alcoves off the main paths, 12 turbolifts would be no problem. The design is such that every turbolift station (other than ones at an end of a branch) lets cars pull out of the way of traffic.
As more decks get developed, more alcoves will be added, but I had envisioned way more than 12 turbolifts running around considering that a vacant one needs to be at least 15 seconds away from any station at any time.
Anyways... I thought it might be helpful to those having problems visualizing this layout to see a more 3D type of representation of the network so far.