I. Whenever the department shall be of the opinion, after a hearing had upon its own motion or upon complaint, that any part of a common carrier of passengers or freight within the state reasonably requires alteration or reconstruction, or that the rules, practices, equipment, appliances, or service of any common carrier in respect to transportation of persons or property within the state are unjust, unreasonable, unsafe, improper, or inadequate, the department shall determine the reconstruction or alteration reasonably required, or the just, reasonable, safe, adequate, and proper rules, practices, equipment, appliances, and service thereafter to be in force or to be provided, and shall fix and prescribe the same by order to be served upon every common carrier to be bound by the order.
II. It shall be the duty of every common carrier to observe and obey every requirement of such order so served upon it, and to do everything necessary or proper in order to secure compliance with and observance of the same by all its officers, agents, and employees.