From Wazeopedia
Update approval:
The Waze routing algorithm has a method of [[Routing penalties#Road_configurations|penalizing]] some double-left and double-right turns. This can prevent U-turns at H or # style intersections on divided and parallel roads.
It is useful for preventing the sequence of two turns that would make up the U-turn, while still allowing the individual turns. However, if either of the two turns making up the U-turn is illegal or impossible, disallow that turn instead. The U-turn will then not be routed, and the following penalty does not matter.