Sec. 547.405.  EMERGENCY BRAKES REQUIRED.  (a)  A vehicle used to tow another vehicle equipped with air-controlled brakes shall be equipped with the following means, together or separate, for applying the trailer brakes in an emergency:
(1)  an automatic device that applies the brakes to a fixed pressure from 20 to 45 pounds per square inch if the towing vehicle's air supply is reduced;  and
(2)  a manual device to apply and release the brakes that is readily operable by a person seated in the operator's seat and arranged so that:
(A)  its emergency position or method of operation is clearly indicated;  and
(B)  its use does not prevent operation of the automatic brakes.
(b)  In addition to the single control device required by Section 547.403, a vehicle used to tow another vehicle equipped with vacuum brakes shall be equipped with a second control device that:
(1)  is used to operate the brakes on a towed vehicle in an emergency;
(2)  is independent of brake air, hydraulic, or other pressure and independent of other controls, unless the braking system is arranged to automatically apply the towed vehicle's brakes if the pressure for the second control device on the towing vehicle fails;  and
(3)  is not required to provide modulated braking.
(c)  Subsections (a) and (b) do not apply to a vehicle that tows another vehicle as a commodity when at least one set of wheels of the towed vehicle is on the roadway.
(d)  A trailer, semitrailer, or pole trailer that is equipped with air or vacuum brakes or that has a gross weight heavier than 4,500 pounds shall be equipped with brakes that:
(1)  operate on all wheels required to have brakes under Section 547.402; and
(2)  are promptly applied automatically and remain applied for at least 15 minutes in case of a breakaway from the towing vehicle.
(e)  A motor vehicle used to tow a trailer, semitrailer, or pole trailer equipped with brakes shall be equipped with service brakes arranged so that, in case of a breakaway of the towed vehicle, the towing vehicle is capable of stopping by use of its service brakes.
Acts 1995, 74th Leg., ch. 165, Sec. 1, eff. Sept. 1, 1995.
Amended by: 
Acts 2019, 86th Leg., R.S., Ch. 854 (H.B. 2810), Sec. 1, eff. September 1, 2019.
Acts 2019, 86th Leg., R.S., Ch. 860 (H.B. 2837), Sec. 5, eff. September 1, 2019.