It is hereby declared to be the policy of the legislature to provide for proper regulation of the transportation of passengers by motor vehicle upon the highways of this state, subject to the provisions of this chapter so administered as to recognize and preserve the inherent advantages of such transportation, to promote safe, adequate, economical and efficient service by passenger motor carriers, and reasonable charges therefor, without unjust discrimination, undue preferences or advantages or unfair or destructive competitive practices; to improve the relations between and coordinate transportation by and the regulation of passenger motor carriers and other carriers; to develop and preserve a highway passenger transportation system properly adapted to the needs of the state; and to promote safety upon its highways in the interest of its citizens. The provisions of this chapter shall be administered and enforced with a view to carrying out the above declaration of policy.