Tex. Transp. Code § 601.451
In this subchapter, "implementing agencies" means:
Added by Acts 2005, 79th Leg., Ch. 892 (S.B. 1670), Sec. 1, eff. September 1, 2005.
Acts 2009, 81st Leg., R.S., Ch. 933 (H.B. 3097), Sec. 2J.02, eff. September 1, 2009.