으니

Since, now that

Gives a reason and then says what follows from it — since the road is controlled, take another way; it may cause drowsiness, so be careful. Several of these lines pair it with an instruction or a request, which is its most natural home. It is the trimmer sibling of 으니까: the meaning is the same, but 으니까 is ordinary conversation while 으니 sounds tighter and more written.

Register: neutral to slightly formal