Rails - next steps

I've pushed the Rails app for Android a bit further:

• Added pinch zoom function to allow display area to be zoomed out (so you can see wider area)
• Added signal control ability - so you can now control the signals and train routes.

Both of these work - and operating the signals is quite fun, however:

• Any half-decent area of track is too big to be able to see all the signals on screen at once, so you end up scrolling around a lot to set up routes.  Which is a pain.
• You can zoom out, but then it's harder to tap the signals to set the routes.
• When you zoom out, the bitmaps don't scale very well and alias quite badly.

So, some progress, some problems and I'm not sure what to do about this at the moment.