It shall be the duty of the commission:

(1) To regulate common carriers by motor vehicle as provided in this chapter, and, to that end, the commission may establish reasonable rules and requirements with respect to adequate service, transportation of passengers, baggage, freight and express, uniform systems of accounts, records and reports, preservation of records, qualifications and maximum hours of service of employees and safety of operation and equipment.

(2) To regulate contract carriers by motor vehicle as provided in this chapter, and, to that end, the commission may establish reasonable requirements with respect to uniform systems of accounts, records and reports, preservation of records, qualifications and maximum hours of service of employees and safety of operation and equipment.

(3) To regulate brokers as provided in this chapter, and, to that end, the commission may establish reasonable requirements with respect to the licensing, financial responsibility, accounts, records, reports, operations and practices of any such person or persons.

(4) To supervise and regulate common carriers in all matters affecting the relationship between such common carriers and the traveling and shipping public.

(5) To administer, execute and enforce all provisions of this chapter and to make all necessary orders in connection therewith and to prescribe rules, regulations and procedure for such administration.

(6) To inquire into the organization of motor carriers and brokers and into the management of their business, to keep itself informed as to the manner and method in which the same is conducted and to transmit to the legislature, from time to time, such recommendation as to additional legislation relating to such carriers or brokers as the commission may deem necessary.

(7) To establish from time to time such just and reasonable classification of brokers or of groups of carriers, included in the term "common carrier by motor vehicle" or "contract carrier by motor vehicle," as the special nature of the services performed by such carriers or brokers shall require and such just and reasonable rules, regulations and requirements, consistent with the provision of this chapter, to be observed by the carriers or brokers so classified or grouped as the commission deems necessary or desirable in the public interest.

(8) Upon complaint in writing to the commission by any person, state board, organization or body politic or upon its own initiative without complaint, to investigate whether any motor carrier or broker has failed to comply with any provision of this chapter, or with any requirement established pursuant thereto. If the commission, after notice and hearing, finds upon any such investigation that the motor carrier or broker has failed to comply with any such provision or requirement, the commission shall issue an appropriate order to compel the carrier or broker to comply therewith.

After a decision, order or requirement has been made by the commission in any proceeding under this chapter, any party thereto may make application to the commission for reconsideration or rehearing of the same, or of any matter determined herein, and it shall be lawful for the commission in its discretion to grant such reconsideration or a rehearing, if sufficient reason therefor is made to appear. Such application shall be filed within 30 days after date of such decision, order or requirement; provided, that the commission may by order extend such time for not more than 30 days additional. Applications for reconsideration or rehearing shall be governed by such general rules as the commission may prescribe. No such application shall excuse any motor carrier or broker from complying with or obeying any decision or requirement of the commission or operate in any manner to stay or postpone the enforcement thereof without the special order of the commission. If, after such reconsideration or rehearing, it shall appear that the original decision, order or requirement is in any respect unjust or unreasonable, the commission may reverse, change or modify the same accordingly. Any decision, order or requirement made after such reconsideration or rehearing shall be subject to the same provisions as an original decision, order or requirement; provided, however, it shall not be subject to any further application for reconsideration or rehearing by the commission.