MOTOR VEHICLES ‑- HIGHWAYS ‑- FEDERAL ‑- FOREST SERVICE ROADS ‑- APPLICABILITY OF STATE 'RULES OF ROAD The Washington public service commission has the authority to adopt and enforce rules and regulations relating to the safety of operations of motor freight carriers and auto transportation companies including the regulation of vehicle equipment and driver qualifications if such regulations are not in conflict with those of the state commission on equipment or the provisions of chapter 46.37 RCW.