Scott - the 3 in the center are 'identification' lights, the ones at the outside are 'clearance' lights - they do indicate specific things to commercial truckers at night or in the fog!
from our provincial MVcode:
Clearance lamps:
1) A commercial vehicle may be equipped with 2 amber clearance lamps mounted on the front of the vehicle, near or at the top of the vehicle, in such a manner as to indicate the overall width of the vehicle.
(2) A truck tractor must be equipped with amber clearance lamps mounted on the front of the vehicle.
(3)A vehicle with an overall width of 2.05m [6.8'] or more, or a trailer or semitrailer having a gross weight in excess of 1,400 kg, must illuminate
(a) a clearance lamp,
(i) mounted on the front at each side of the vehicle, displaying only amber .... or
(ii) mounted on the front of the vehicle, that is capable of displaying amber, green or white light, but only if the vehicle was manufactured before January 1, 1959, and
(b) a clearance lamp, mounted on the rear at each side of the vehicle, that is capable of displaying only red light visible from the rear.
(4) Subsection (3) does not apply to a pole trailer.
(5) Clearance lamps on vehicles manufactured after December 31, 1993 must be mounted near or at the top of the vehicle in such a manner as to indicate the overall width of the vehicle.
[most big trucks here have the clearance lights on the rear view mirrors nowadays]
Identification lamps
(1) A commercial vehicle may be equipped with 3 identification lamps, mounted in a row on the front of the vehicle at or near the top, that are capable of displaying only amber light.
(2) A commercial vehicle with an overall width of 2.05 m or more may be equipped with 3 identification lamps,
(a) mounted in a row on the rear of the vehicle at or near the top, or
(b) mounted below the rear door of a van trailer when the top header is 2.5 cm or less in width
......
Bill
