Railways heretofore constructed or that may hereafter be constructed in this state are hereby declared public highways, and all railroad, sleeping car, telegraph, telephone and transportation companies of passengers, intelligence and freight, are declared to be common carriers and subject to legislative control; and the legislative assembly shall have power to enact laws regulating and controlling the rates of charges for the transportation of passengers, intelligence and freight, as such common carriers from one point to another in this state; provided, that appeal may be had to the courts of this state from the rates so fixed; but the rates fixed by the legislative assembly or board of railroad commissioners shall remain in force pending the decision of the courts.