(b) The department shall be governed and its corporate powers shall be exercised by a board of directors. The board shall consist of 11 members, including the secretary of transportation, who shall serve ex officio as chair. The governor shall appoint 10 members: 1 of whom shall be a rider, as defined in section 1 of chapter 161A; 1 of whom shall have experience in the field of public or private finance; 1 of whom shall have experience in transportation planning and policy; 1 of whom shall have experience in civil engineering; 1 of whom shall have experience in the field of public or private finance or transportation planning and policy; 1 of whom shall have municipal government experience in 1 of the fourteen cities and towns, as defined in said section 1 of said chapter 161A; 1 of whom shall have municipal government experience in 1 of the 51 cities and towns, as defined in said section 1 of said chapter 161A; 1 of whom shall have municipal government experience in 1 of the other served communities, as defined in said section 1 of said chapter 161A; 1 of whom shall have municipal government experience in a city or town not part of the area constituting the authority, as defined in said section 1 of said chapter 161A; and 1 of whom shall be a representative of a labor organization selected from a list of 3 nominees provided by the Massachusetts State Labor Council, AFL-CIO. Four of the members, other than the chair, shall serve for terms that are coterminous with the governor; provided, however, that at least 3 of the coterminous members shall have experience in transportation policy, public finance or civil engineering and at least 1 of the coterminous members shall be a rider. The 6 remaining members appointed by the governor shall serve for terms of 4 years. Not more than 6 of the directors, not including the chair, shall be members of the same political party. The directors, with the exception of the chair, shall serve without compensation but may be reimbursed for actual and necessary expenses reasonably incurred in the performance of their duties, including reimbursement for reasonable travel; provided, however, that reimbursement shall not exceed $3,000 annually per director. A person appointed to fill a vacancy in the board of directors shall serve only for the unexpired term of the former member. A director shall be eligible for reappointment. A director may be removed by the governor for cause. The board shall annually elect 1 of the directors to serve as vice-chair.