(a) A subregional board is composed of 11 members.
(b) If the entire county of the principal municipality is included in the authority, the subregional board consists of:
(1) five members appointed by the governing body of the principal municipality;
(2) five members appointed by the commissioners court of the county of the principal municipality; and
(3) one member appointed by the governing body of a municipality that is in the authority and has a population of more than 100,000.

(c) If Subsection (b) does not apply, the subregional board shall be appointed as follows:
(1) the commissioners court of the county of the principal municipality shall appoint at least three members to represent:
(A) the unincorporated areas and municipalities in the county that are not otherwise represented on the subregional board; and
(B) the municipalities that have entered into a contract with the authority to receive services; and
(2) the remaining members shall be apportioned to the municipalities confirmed as all or part of the subregion according to the ratio that the population of each unit of election bears to the total population of the area confirmed as the subregion.
(d) Units of election that do not receive at least one member are to be aggregated with the county to determine population represented by the county, and appropriate additional members, if any, are to be so apportioned to the county.
(e) Units of election that are entitled to one or more members are to have the number of members rounded to the nearest whole number to determine actual apportionment.
(f) The principal municipality shall make its appointments to the board so that at least one of the appointees is designated to represent the interests of the transportation disadvantaged.
(g) An elected officer of the state or a political subdivision of this state who is not prohibited by the Texas Constitution from serving on the board is eligible, as an additional duty of office, to serve on the board. An elected officer who is a board member is not entitled to receive compensation for serving as a member but is entitled to reimbursement for reasonable expenses incurred in performing duties as a member.