Path deform doesn't strike me as the best way to do this.
It will bend the individual tracks.
Have you considered a path constraint controller. This will take a little more time, but might be better for what you need.
*edit* I just made a scene with some tracks and the path constraint controller works great.
This is defiantly the way to go as far as I can see and it is so easy to keyframe.
1) Make one track segment
2) Draw the Track spline
3) Assign a Path constraint position controller to the segment with 'allow upside down' ON and 'follow' ON
4) Check it runs along the path where you want it to because it will be hard to edit this path later *edit* Actually, not that hard.
5) Copy the segment and go to keyframe 0.
6) Tweak the 'along path %age' until it is the right distance from the first segment
7) Repeat 5,6 and 7 until all the track is done
8) Key frame all the 'along path %age' together whilst maintaining the distances
9) Profit
My test ended up looking like this:
