Fast Splitters are splitters which are twice as fast as normal Splitters, but only 67% as fast as Express splitters. The items are placed in 1:1 relation on the outgoing belts. Splitters have a filtering facility and input and output priorities as described in the Belt Transport System.
Changed splitters so they work more intuitively. The left and right lane splitting is now completely independent. The decision whether item goes to left or right output is now independent of the item type.