Sec. 2. (a) The requirements in this chapter setting forth the distance from which certain lamps and devices are required to render objects visible or within which the lamps or devices are required to be visible apply:
(1) during the times stated in IC 9-21-7-2;
(2) with respect to a vehicle without load; and
(3) when upon a straight, level, unlighted highway under normal atmospheric conditions;
unless a different time or condition is expressly stated.
(b) The mounted heights of lamps or devices required in this chapter are measured from the center of the lamp or device to the level ground upon which the vehicle stands when the vehicle is without a load.