Idaho Code § 49-927: Number of driving lamps required or permitted.

(1) At all times specified in section 49-903, Idaho Code, at least two (2) lighted lamps shall be displayed, one (1) on each side at the front of every motor vehicle other than a motorcycle or motor-driven cycle, except when the vehicle is parked subject to the requirements governing lights on parked vehicles.

(2) Whenever a motor vehicle equipped with required head lamps is also equipped with any auxiliary lamps, a spot lamp, or any other lamp on the front projecting a beam of intensity greater than three hundred (300) candlepower, not more than a total of four (4) lamps on the front of a vehicle shall be lighted at any one (1) time when upon a highway.