Minecart Swapper [1.8+]

Hi guys! It's Aschie4589. Today I have for you an amazing build! It's a very compact and resource friendly minecart station, that uses a few pistons and slimeblocks to swap the trains!
Think of it: never again will you have to use two parallel tracks for your more complicated railways! Another advantage of this design is that, should something go wrong, it will automatically send all the minecarts but one away, repairing itself!
Plus, you can use it with all the types of minecart, and even when someone (or something) is riding it!
Tell me what you think could be improved, I'm open to suggestions :D
See you!