What type of carrier is the "backbone of the transportation industry"?

Question

Quizplus · Accepted Answer

Common carriers are considered the backbone of the transportation industry as they provide services to the general public and transport a wide variety of goods and materials. Private carriers are owned by a company and transport their own goods, while institutional carriers primarily serve specific industries or organizations. Bulk carriers specialize in transporting large quantities of a specific product or material.

What Type of Carrier Is the "Backbone of the Transportation