Iowa Code § 306.10: Power to establish, alter, or vacate.

In the construction, improvement, operation or maintenance of any highway, or highway system, the agency which has control and jurisdiction over such highway or highway system, shall have power, on its own motion, to alter or vacate and close any such highway or railroad crossing thereon, and to establish new highways or railroad crossing thereon which are or are intended to become a part of the highway system over which said agency has jurisdiction and control.