(a) It shall be the duty of the commission to investigate the books and papers of all railroad companies doing business in this state in order to ascertain if the rules and regulations of the commission have been complied with, to make personal visitation to railroad offices, stations, and other places of business for the purpose of examinations, and to make rules and regulations concerning such examinations, which rules and regulations shall be observed and obeyed as the other rules and regulations of the commission.

(b) The commission shall have full power and authority to examine any person, including agents and employees of railroad companies, under oath or otherwise, in order to procure the information necessary to make just and reasonable freight and passenger rates and to ascertain whether rules and regulations of the commission are observed or violated. The commission shall have the power to make necessary and proper rules and regulations concerning such examinations, which rules and regulations shall be obeyed and enforced as all other rules and regulations of the commission.