S.D. Codified Laws § 49-16A-50
Each railroad authorized to construct, operate, or maintain roads within this state, subject to the provisions of this chapter, may construct its roads across, along, or upon any stream of water, watercourse, street, highway, toll road, turnpike, levee, river front, or public landing, or canal, which its route intersects or touches; may carry any highway, street, toll road, or turnpike which it touches, intersects, or crosses, over or under its track, as may be most expedient for the public good; and may change the course or direction of any highway, street, turnpike, or toll road when made necessary or desirable to secure more easy ascent or descent by reason of any embankment or cut made in the construction of its roads, and take land necessary therefor, provided that such highway or road is not changed from its original course by more than ninety-nine feet, nor its distance lengthened for more than eighty-two and one-half feet.
SDCL 49-16A-50