It is hereby declared to be the policy of the state to regulate transportation of property by motor carriers upon its publicly used highways in such manner as to recognize and preserve the inherent advantages of transportation, and to foster sound economic conditions in transportation and among carriers engaged therein in the public interest; and in connection therewith to:

(1)  Promote adequate, economical, and efficient service by motor carriers and reasonable charges therefor without unjust discriminations, undue preferences, or advantages or unfair or destructive competitive practices;

(2)  Improve the relations between, and coordinate transportation by and the regulations of motor carriers and other carriers;

(3)  Develop and preserve a highway transportation system properly adapted to the needs of the commerce of the state; and

(4)  Promote safety upon its publicly used highways in the interest of its citizens.