Requesting help with Minecart rail changer...(logic circuits)

Here is a gallery showing what is going on. Basically, there are four switches that dictate the destination for the cart. When a switch is hit, three rail exchanges are flipped to their proper positions. I am going through the logics of it myself, but would love any feedback or tips. Space isn't necessarily an issue, but I've gotten the rest of the contraption pretty compact so far.

Thanks!