(a) Every vehicle upon a highway within this state at any time from a half hour after sunset to a half hour before sunrise and at any other time when there is not sufficient light to render clearly discernible persons and vehicles on the highway at a distance of 500 feet ahead shall display lighted lamps and illuminating devices as hereinafter respectively required for different classes of vehicles, subject to exceptions with respect to parked vehicles as hereinafter stated. When lighted lamps and illuminated devices are required by law no vehicle shall be operated upon any highway of this state with only the parking lights illuminated on the front of the vehicle.

    (b) Whenever requirement is hereinafter declared as to the distance from which certain lamps and devices shall render objects visible or within which such lamps or devices shall be visible, said provisions shall apply during the times stated in paragraph (a) of this section upon a straight, level, unlighted highway under normal atmospheric conditions unless a different time or condition is expressly stated.

    (c) Whenever requirement is hereinafter declared as to the mounted height of lamps or devices, it shall mean from the center of such lamp or device to the level ground upon which the vehicle stands when such vehicle is without a load.