The commission may, upon complaint or upon its own motion, prescribe and authorize just and reasonable rates for the transportation of persons or property for any public service company subject to regulation by the commission as to rates and service, whenever and as often as it deems necessary or proper. The commission shall, before any hearing upon the complaint or motion, notify the complainants and the carrier concerned of the time and place of the hearing by giving at least ten days' written notice thereof, specifying that at the time and place designated a hearing will be held for the purpose of prescribing and authorizing the rates. The notice is sufficient to authorize the commission to inquire into and pass upon the matters designated in this section.

In exercising this power, the commission may use any standard, formula, method, or theory of valuation reasonably calculated to arrive at the objective of prescribing and authorizing just and reasonable rates.

In the exercise of this power, the commission may consider, in addition to other factors, the following:

(1) The effect of the rates upon movement of traffic by the carriers;

(2) The public need for adequate transportation facilities, equipment, and service at the lowest level of charges consistent with the provision, maintenance, and renewal of the facilities, equipment, and service; and

(3) The carrier need for revenue of a level that under honest, efficient, and economical management is sufficient to cover the cost, including all operating expenses, depreciation accruals, rents, and taxes of every kind, of providing adequate transportation service, plus an amount equal to the percentage of that cost as is reasonably necessary for the provision, maintenance, and renewal of the transportation facilities or equipment and a reasonable profit to the carrier. The relation of carrier expenses to carrier revenues may be deemed the proper test of a reasonable profit.