Iowa Code § 307.36
It is the intent of the general assembly that not later than July 1, 1992, the state department of transportation shall dispose of all right-of-way owned by the department and not needed for projects. In determining need, the department shall consider both its five-year program requirements and its long-range, statewide corridor development needs, including the development of the network of commercial and industrial highways. The department may also act to preserve right-of-way for improvements to the network of commercial and industrial highways by acquiring options, easements, rights of first refusal, or other property interests less than fee title. In determining need based upon long-range, statewide corridor development, the department shall give careful consideration to economically depressed urban areas not served directly by the national system of interstate and defense highways.
Iowa Code § 307.36