Idaho Code § 62-405

Every railroad corporation must have printed and conspicuously posted on the inside of its passenger cars its rules and regulations regarding fare and conduct of its passengers; and in case any passenger is injured on or from the platform of a car, or on any baggage, wood, gravel or freight car, in violation of such printed regulations, or in violation of positive verbal instructions or injunctions given to such passenger in person by any officer of the train, the corporation is not responsible for damages for such injuries, unless the corporation failed to comply with the provisions of the preceding section.