split stairway
Stairs whose pathway forks into clearly distinct directions on the way up or down.
A split stairway consists of different flights or sections which come together or fork into significantly different directions along their path. Any number of paths can be joined in such a stairway, and at any number of points. The split may occur at or between floor levels, but if it occurs at a floor level then the divergent path should be considered inseparable from the other pathways in order to be considered part of a split stairway.
The paths may join or separate at several points, and more than two branches are allowed. A single symmetrical fork is only one possible arrangement.
A division at floor level counts only when the divergent path is inseparable from the other stair pathways. Separate stairs reached across an intervening floor are not joined merely by serving that floor.