I'm trying to figure out how to make a rollercoastertrack - I did the basics:
Extrude a profile along a curve that has the bends I'd like the track to make. I tried this with extruding a curve along that track's curve and by extruding a poly along it - works fine so far.
My question is: how can I make it so I can control the direction a part of the track (extruded geometry) leans, i.e. if the cart that one day should ride upon and along it leans outward, inward or even does a corkscrewy spin along the track?

I've looked into some material about motionpaths/flowpaths, but could not produce anything close. I feel I'm on the right way with deformers, though - am I?

I'd be glad for any hints or tipps!

sidequest: where can one find the option to display a curve's direction like blender does?