The use of the public highways for the transportation of passengers for compensation is a business affected with the public interest. It is the purpose of this chapter to preserve for the public full benefit in use of public highways consistent with the needs of commerce, without unnecessary congestion or wear and tear upon such highways; to secure to the people safe, adequate and dependable transportation by carriers operating upon such highways; and to secure full and unrestricted flow of traffic by motor carriers over such highways which will adequately meet reasonable public demands by providing for the regulation of all transportation agencies with respect to safety of operations and accident indemnity so that safe, adequate and dependable service by all necessary transportation agencies shall be maintained, and the full use of the highway reserved to the public.