Section 5. There shall be an advisory board to each authority consisting of the city manager, in the case of a Plan D or Plan E city, or the mayor of each other city, and the chairman of the board of selectmen of each town having such board, or the town manager or town administrator of each other town. Each mayor or city manager and each chairman, may, by writing filed with the authority, from time to time appoint a designee to act for him on the advisory board. Each city and town shall have one vote on the advisory board plus additional votes and fractions thereof determined by multiplying one and one half times the total number of cities and towns in the authority by a fraction of which the numerator shall be the total amount of all assessments made by the state treasurer to such city or town under this chapter and the denominator shall be the total amount of all such assessments made by the state treasurer to such cities and towns. The total vote of each city and town shall each year be determined by the authority and delivered in writing to the advisory board thirty days after the state treasurer has sent his warrants for payments to the cities and towns. The determination of votes shall be based upon the most recent annual assessment. Until the first such assessment, the fraction specified above shall be replaced by a fraction of which the numerator shall be the population of each such city or town and the denominator shall be the total population of all cities and towns in the authority. Population data shall be determined in accordance with the latest decennial census made by the United States Department of Commerce.

One representative of the disabled commuter population shall serve on the advisory board as a voting member for a term of 1 year. Each city and town in the region, on a rotating basis as determined by the board, shall appoint a representative successively; provided, however, that the representative of the disabled commuter population and the representative of the rider community shall not be appointed by the same city or town in the region. The mayor or city manager and the chairman, town manager or town administrator shall appoint a resident of the city or town for this purpose. This representative shall be mobility impaired, have a family member who is mobility impaired, be a caretaker of a person who is mobility impaired or work for an organization that serves the needs of the physically disabled. The representative of a city or town may be reappointed after representatives from the other cities and towns within the region have served their 1–year terms.

One representative of the rider community population shall serve on the advisory board as a voting member for a term of 1 year. Each city and town in the region, on a rotating basis as determined by the board, shall appoint a representative successively; provided, however, that the representative of the disabled commuter population and the representative of the rider community shall not be appointed by the same city or town in the region. The mayor or city manager and the chairman, town manager or town administrator shall appoint a community rider for this purpose from a list of at least 5 persons nominated by the Massachusetts AFL–CIO and its regional councils. The representative of a city or town may be reappointed after representatives from the other cities and towns within the region have served their 1–year terms.

The advisory board shall act by majority vote, except that it may delegate its power of approval to an executive committee formed and elected pursuant to duly adopted by-laws of the board and constituting among its members at least a majority of the total vote of the board, and may, at any time, revoke such delegation. Until the board has adopted by-laws and elected officers, the mayor or city manager of the city having the largest population or in the case of an authority composed entirely of towns, the selectmen of the town having the largest population within the area constituting the authority may call meetings of the advisory board by sending notice to each other mayor or city manager and chairman and shall preside at such meetings.

The advisory board may incur expenses, not to exceed ten thousand dollars annually, for stenographic and clerical work, and such expenses shall be paid by the authority.