(a) The commission is exempt from taxation of or assessments on:
(1) a toll project or system;
(2) property the department acquires or uses under this subchapter; or
(3) income from property described by Subdivision (1) or (2).
(b) Bonds issued under this subchapter and income from the bonds, including any profit made on the sale or transfer of the bonds, are exempt from taxation in this state.