All the dogs on the train would have to be turned around (lifting dogs, anti-rollbacks). The polarity of the anti-rollback generator system, which took them a month to get working properly, would have to be reversed. But the main reason you're not going to see them turn any of their coasters around backwards anytime soon is that turning the train backwards changes the dynamics of the ride. Spots that would pitch a rider into the seat going forward, for instance, will *eject* a rider going backward. That kind of thing.
Nope, I don't think it's gonna happen.
--Dave Althoff, Jr.