Ala. Admin. Code r. 770-X-10-.17-4-1-.12

Current through Register Vol. 43, No. 1, October 31, 2024

Section 770-X-10-.17-4-1-.12 - Breakaway And Emergency Braking

(1) Every motor vehicle, if used to tow a trailer equipped with brakes, shall be equipped with means for providing that in case of breakaway of such trailer the service brakes of the towing vehicle will be sufficiently operative to stop the towing vehicle.

(2) Every truck or truck tractor equipped with air brakes, when used for towing other vehicles equipped with air brakes, shall be equipped with two means of activating the emergency features of the trailer brakes. One of these means shall operate automatically in the event of reduction of the towing vehicle air supply to a fixed pressure which shall not be lower than 20 pounds per square inch nor higher than 45 pounds per square inch. The other means shall be a manually-controlled device readily operable by a person seated in the driving seat. Its emergency position or method of operation shall be clearly indicated. In no instance may the manual means be so arranged as to permit its use to prevent operation of the automatic means. The automatic and manual means required by this section may be, but are not required to be, separate.

(3) Every truck tractor and truck when used for towing other vehicles equipped with vacuum brakes shall have, in addition to the single control required to operate all brakes of the combination, a second manual-control device which can be used to operate the brakes on the towed vehicle in emergencies. Such second control shall be independent of brake air, hydraulic and other pressure, and independent of other controls, unless the braking system be so arranged that failure of the pressure on which the second control depends will cause the towed vehicle's brakes to be applied automatically. The second control is not required by this rule to provide modulated or graduated braking.

(4) Every trailer required to be equipped with brakes shall be equipped with brakes of such character as to be applied automatically and promptly upon breakaway from the towing vehicle, and means shall be provided to maintain application of the brakes on the trailer in such case for at least fifteen minutes.

(5) Air brake systems installed on towed vehicles shall be so designed, by the use of "no-bleed-back" relay emergency valves or equivalent devices, that the supply reservoir used to provide air for brakes shall be safeguarded against backflow of air to the towing vehicle upon reduction of the towing vehicle air pressure.

Ala. Admin. Code r. 770-X-10-.17-4-1-.12

Effective January 1978. Filed with LRS February 5, 2013. Filed for Codification in the Alabama Administrative Code by the Alabama Public Service Commission on February 5, 2013, pursuant to Code of Ala. 1975, § 41-22-7.

Author: Alabama Public Service Commission

Statutory Authority:Code of Ala. 1975, §§ 37-3-5, 37-3-7.