Idaho Code § 40-302
The board shall be composed of seven (7) members to be appointed by the governor. Not more than four (4) members shall at any time belong to the same political party. Members shall be well informed and interested in the construction and maintenance of public highways and highway systems, and their selection and appointment shall be made solely with regard to the best interests of the various functions of the board. At least one (1) member shall have special training, experience or expertise in the field of aeronautical transportation. Each member at the time of his appointment shall have been a citizen, resident and taxpayer of the state of Idaho and of the district from which he is appointed for at least five (5) years. During his tenure of office no member shall hold or occupy any federal, state, county, or municipal elective or other appointive office, or any office in any political party.
Idaho Code § 40-302