I love the idea of building both new stops on the existing subways and building whole new subway lines. You'd have to learn BA3 to be able to contribute to construction.
Oooo. +1! Fun! (There would, of course, have to be pre-established routes for us to build on. Also, I think the projects should be very hard, taking hard work from many players over a really long time.)
I can see us all underground somewhere, a hoard of glitchen swinging their fancy picks at a barely yielding rock face. We come and go but the tunnel is never really empty. After weeks of toil we stop momentarily and hear... voices? metallic sounds? The effort is redoubled and soon a breakthrough is achieved. We stand on small piles of rubble and peer through a window-sized hole, and there on the other side is another party of glitchen who have been working just as we were. There's a tale we could tell the newbies...
Having multiple stations available for development at once, and having a high-level skill prerequisite for working on them would go some way to helping with the congestion there was at old-style street projects, but would probably not be enough -- perhaps a combination of fox-preserve-style limits on how many glitchen can enter and AL-style limits on how long they can stay? (The air in a subway tunnel is likely none too good, after all.)
Maybe the higher level players could work on the tunnels and the lower levels could build the stations, kind of like building an extremely complex tower. That way every one could contribute in some way.
I would switch those around, because historically, the unskilled dug the tunnels, and the slightly-more-skilled built the buildings. ;)
Maybe it could be along the lines of, one work unit =x seconds of effort if you have level 1 mining, takes a couple less seconds each additional level. It could work the same way for the building, but with Engineering + Construction for the skills?
So BA3 would be only useful for.. this? I don't understand how a custom made subway station would work. How about they let everyone just contribute to a whole new preset subway station? or just pop in the new subway line into existence without any projects..
Pretty sure BA3 is going to be all about permits that allow things like parties, and special events. BA2 is already restricted to building projects, It's more important to build a party house before you can have a party in it, so to speak. So odds are we will only need BA2 for something like that anyway.
I like the idea of a extended subway as well but I am not so keen on the idea that I will have to learn BA3. Maybe it could give you some sort of advantage but I do not like the idea of only letting people with that skill work on the subway stations.