321.392  Clearance and identification lights.
  Every motor truck, and every trailer or semitrailer of over three thousand pounds gross weight, shall be equipped with the following lighting devices and reflectors in addition to other requirements of this chapter, and such devices shall be lighted at the times mentioned in section 321.384.
  1.  Every motor truck, whatever its size shall have the following:
  a.  On each side, one reflector, at or near the rear; and
  b.  On the rear, two reflectors, one at each side.
  2.  Every motor truck, eighty inches or more in width shall have the following in addition to the requirements of subsection 1:
  a.  If thirty feet or less in overall length:
  (1)  On the front, two clearance lamps, one at each side; and
  (2)  On the rear, two clearance lamps, one at each side.
  b.  If more than thirty feet in overall length:
  (1)  On the front, two clearance lamps, one at each side;
  (2)  On each side, two side-marker lamps, one at or near the front, and one at or near the rear, and an additional reflector at or near the front; and
  (3)  On the rear, two clearance lamps, one at each side.
  3.  Every truck tractor or road tractor shall have the following:
  a.  On the front, two clearance lamps, one at each side if the tractor cab is as wide as, or wider than, the widest part of the vehicle or vehicles towed;
  b.  On each side, one side-marker lamp at or near the front; and
  c.  On the rear, one tail lamp.
  4.  Every trailer or semitrailer having a gross weight in excess of three thousand pounds shall have the following:
  a.  On the front, two clearance lamps, one at each side, if the trailer is wider in its widest part than the cab of the vehicle towing it;
  b.  On each side, one side-marker lamp at or near the rear; two reflectors, one at or near the front and one at or near the rear; and
  c.  On the rear, two clearance lamps, one at each side; one stop light; one tail lamp; and two reflectors, one at each side.
  5.  Every motor truck or combination of motor truck and trailer having a length in excess of thirty feet or a width in excess of eighty inches shall be equipped with three identification lights on both front and rear. Each such group shall be evenly spaced not less than six nor more than twelve inches apart along a horizontal line near the top of the vehicle.
[C31, 35, §5044-d1, -d2, 5105-c19; C39, §5034.01; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §321.392]
For applicable scheduled fine, see §805.8A, subsection 3