Tex. Transportation Code § 451.110

Sec. 451.110. PURCHASES: COMPETITIVE BIDDING. (a) Except as provided by Subsection (c) and by Subchapter Q, a board may not contract for the construction of an improvement or the purchase of any property, except through competitive bidding after notice of the contract proposal. The notice must be published in a newspaper of general circulation in the area in which the authority is located at least once each week for two consecutive weeks before the date set for receiving the bids. The first notice must be published at least 15 days before the date set for receiving bids.

(b) The board may adopt rules on:

(1) the taking of bids;

(2) the awarding of contracts; and

(3) the waiver of the competitive bidding requirement:

(A) if there is an emergency;

(B) if there is only one source for the purchase; or

(C) except for a contract for construction of an improvement on real property, if:

(i) competitive bidding is inappropriate because the procurement requires design by the supplier and if competitive negotiation, with proposals solicited from an adequate number of qualified sources, will permit reasonable competition consistent with the procurement; or

(ii) it is ascertained after solicitation that there will be only one bidder.

(c) Subsection (a) does not apply to a contract for:

(1) $100,000 or less;

(2) the purchase of real property;

(3) personal or professional services; or

(4) the acquisition of an existing transit system.