56.14132—Horns and backup alarms.
(a)
Manually-operated horns or other audible warning devices provided on self-propelled mobile equipment as a safety feature shall be maintained in functional condition.
(b)
(1)
When the operator has an obstructed view to the rear, self-propelled mobile equipment shall have—
(i)
An automatic reverse-activated signal alarm;
(ii)
A wheel-mounted bell alarm which sounds at least once for each three feet of reverse movement;
(iii)
A discriminating backup alarm that covers the area of obstructed view; or
(iv)
An observer to signal when it is safe to back up.
(2)
Alarms shall be audible above the surrounding noise level.
(3)
An automatic reverse-activated strobe light may be used at night in lieu of an audible reverse alarm.
(c)
This standard does not apply to rail equipment.