There is hereby created a transportation commission, which shall consist of seven voting members appointed by the governor, with the consent of the senate. The present five members of the highway commission shall serve as five initial members of the transportation commission until their terms of office as highway commission members would have expired. The additional two members provided herein for the transportation commission shall be appointed for initial terms to expire on June 30, 1982, and June 30, 1983. Thereafter all terms shall be for six years. No elective state official, state officer, or state employee shall be a member of the commission. At the time of appointment or thereafter during their respective terms of office, four members of the commission shall reside in the western part of the state and three members shall reside in the eastern part of the state as divided north and south by the summit of the Cascade mountains. No more than two members of the commission shall reside in the same county; however, the governor, or his or her designee, shall serve as a nonvoting member of the commission. Commission appointments should reflect both a wide range of transportation interests and a balanced statewide geographic representation. Commissioners may be removed from office by the governor before the expiration of their terms for cause. No member shall be appointed for more than two consecutive terms.