Tex. Transp. Code § 551.455
(a) In addition to the operation authorized by Sections 551.453 and 551.454, the governing body of a municipality may allow a motor carrier to operate, for the purpose of picking up or delivering mail, parcels, or packages, a vehicle bearing license plates issued under Section 551.452 on all or part of a public highway that:
(b) In addition to the operation authorized by Sections 551.453 and 551.454, a county commissioners court may allow a motor carrier to operate, for the purpose of picking up or delivering mail, parcels, or packages, a vehicle bearing license plates issued under Section 551.452 on all or part of a public highway that:
Added by Acts 2017, 85th Leg., R.S., Ch. 119 (H.B. 561), Sec. 1, eff. May 26, 2017.