Iowa Code § 306A.4
Cities and highway authorities having jurisdiction and control over the highways of the state, as provided by chapter 306, are authorized to so design any controlled-access facility and to so regulate, restrict, or prohibit access as to best serve the traffic for which such facility is intended. In this connection such cities and highway authorities are authorized to divide and separate any controlled-access facility into separate roadways by the construction of raised curbings, central dividing sections, or other physical separations, or by designating such separate roadways by signs, markers, stripes, and other devices. No person shall have any right of ingress or egress to, from, or across controlled-access facilities to or from abutting lands, except at such designated points at which access may be permitted, upon such terms and conditions as may be specified from time to time.
Iowa Code § 306A.4