Idaho Code § 62-404

Every railroad corporation must furnish on the inside of its passenger cars, sufficient room and accommodations for all passengers to whom tickets are sold for any one trip, and for all persons presenting tickets entitling them to travel thereon; and when fare is taken for transporting passengers on any baggage, wood, gravel or freight car, the same care must be taken and the same responsibility is assumed by the corporation as for passengers on passenger cars.