Tex. Gov't Code § 660.042
A mileage reimbursement may not exceed the product of:
Added by Acts 1993, 73rd Leg., ch. 268, Sec. 1, eff. Sept. 1, 1993.
Amended by Acts 1997, 75th Leg., ch. 1300, Sec. 9, eff. Sept. 1, 1997.