Tex. Transportation Code § 647.003: TYPE OF VEHICLE ALLOWED.

(a) A carrier may transport migrant agricultural workers only in a:

(1) bus;

(2) truck to which a trailer is not attached; or

(3) semitrailer attached to a truck tractor.

(b) A carrier may not:

(1) attach a trailer to a semitrailer described by Subsection (a)(3); or

(2) use a closed van that does not have windows or a method to ensure ventilation.

Added by Acts 1999, 76th Leg., ch. 62, Sec. 17.34(a), eff. Sept. 1, 1999.