Dear god, I see many people flipping out about the railtracks being gone and demanding refunds...
It will be back. It was removed because the old system was horrible and in my opinion, useless since it was a maze just to navigate the track system. So I am going to completely redo the track system to hopefully make more sense, but it wouldn't have been possible to finish before the Spring update so it will be added back later and completely redone from scratch to make it more efficient and useful.
So please, be patient. Hopefully it will be worth the wait of going a week or so without a draisine.