Tex. Transportation Code § 451.754

(a) In an authority that chooses to meet and confer under this subchapter, the public employer shall recognize an association submitting a petition for recognition signed by a majority of the peace officers employed by the authority, excluding the head of the peace officer department of the authority and the assistant department heads in the rank or classification immediately below that of the department head, as the sole and exclusive bargaining agent for all of the peace officers employed by the authority, excluding the department head and assistant department heads, until recognition of the association is withdrawn by a majority of the peace officers eligible to sign a petition for recognition.

(b) Whether an association represents a majority of the covered peace officers shall be resolved by a fair election conducted according to procedures agreeable to the parties. If the parties are unable to agree on election procedures, either party may request the American Arbitration Association to conduct the election and to certify the results. Certification of the results of an election under this subsection resolves the question concerning representation. The association is liable for the expenses of the election, except that if two or more associations seeking recognition as the bargaining agent submit petitions signed by a majority of the peace officers eligible to sign the petition, the associations shall share equally the costs of the election.