The business of using automobiles to carry goods, referred to as automobile freight, is a major component of automobile transportation (see road transportation). Car freight has the characteristics of wide area, many points, and scattered. Generally, it is a "door-to-door" direct freight transportation between two places, which can save the cost of transit loading and unloading, reduce the difference between the damaged goods and the goods, and shorten the time of the goods in transit. Car freight is also a collection of goods such land transportas railway transportation, waterway transportation, and air transportation.