In connection with the acquisition of real property for new right-of-way or additional right-of-way for any highway to be constructed, relocated, or reconstructed in either rural or urban areas and paid for in whole or in part with federal or state highway funds, the department may prescribe and define in purchase agreements or condemnation proceedings the location, width, nature, and extent of any right of access that may be permitted between such improved highway and the properties from which such right-of-way or additional right-of-way is acquired, but such prescription and definition shall in no case leave such private properties without a reasonable means of egress and ingress to a road.