Idaho Code § 62-421: Equipment of track motor cars with specified electric lights.

Every individual, firm or corporation, operating or controlling any railroad which is a common carrier shall equip each of its track motor cars operated during the period thirty (30) minutes before sunset to thirty (30) minutes after sunrise with:

(1) An electric headlight of sufficient candle power to enable the operator of the car to plainly discern any track obstruction, landmark, warning sign or grade crossing at a distance not less than 300 feet.

(2) A red rear electric light of sufficient candle power to be plainly visible at a distance not less than 300 feet.