Geographical Settings of Rail Lines

Three major types of rail lines can be identified:

Penetration Lines. Their main purpose is to link a port city with its hinterland, particularly in order to access natural resources such as minerals, agricultural products and wood products. It also represented one of the initial stages of rail development, notably in the United States, which later became regional networks linked by transcontinental lines. This type of system is today mainly found in developing countries (Africa and Latin America) and was partially the result of the colonial era. Transporting freight is the dominant function of this type of network, although passenger traffic can be significant.
Local / Regional Networks. They are servicing high density population areas of developed countries with the goal to support massive shipment of freight and passengers. Regions with the highest rail density are Western Europe, the Northeastern part of North America, Coastal China and Japan.
Transcontinental Lines. These lines were mainly established for territorial conquest and the establishment of a national sovereignty. For instance, on the above figure two nations (A and B; similarities with North America intended) are building their own transcontinental lines, even if it involves some level of redundancy. The most relevant examples are in the United States, Canada, Russia and Australia, which have built rail systems of this scale. Today, transcontinental rail lines are being established to attenuate the discontinuity of maritime transportation by transporting containers. They are a chain in the global intermodal transport system.