30 CFR 57.14132 - Horns and backup alarms for surface equipment.
(a) Manually-operated horns or other audible warning devices provided on self-propelled mobile equipment as a safety device shall be maintained in a functional condition.
(1) When the operator has an obstructed view to the rear, self-propelled mobile equipment shall have—
(3) An automatic reverse-activated strobe light may be used at night in lieu of an audible reverse alarm.
Title 30 published on 2013-07-01
no entries appear in the Federal Register after this date.