Author: Dr. Jean-Paul Rodrigue
Transport modes are the means by which passengers and freight achieve mobility. They are mobile transport assets and fall into three basic types; land (road, rail and pipelines), water (shipping), and air.
Transport modes are designed to either carry passengers or freight, but most modes can carry a combination of both. For instance, an automobile has a capacity to carry some freight while a passenger plane has a bellyhold that is used for luggage and cargo. Each mode is characterized by a set of technical, operational and commercial characteristics. Technical characteristics relate to attributes such as speed, capacity, and motive technology while operational characteristics involve the context in which modes operated, including speed limits, safety conditions or operating hours. The demand for transport and the ownership of modes are dominant commercial characteristics.
a. Road transportation
Road infrastructures are large consumers of space with the lowest level of physical constraints among transportation modes. However, physiographical constraints are significant in road construction with substantial additional costs to overcome features such as rivers or rugged terrain. While historically road transportation was developed to support non-motorized forms of transportation (walking, domestic animals and cycling at the end of the 19th century), it is motorization that has shaped the most its development since the beginning of the 20th century.
Road transportation has an average operational flexibility as vehicles can serve several purposes but are rarely able to operate outside roads. Road transport systems have high maintenance costs, both for the vehicles and infrastructures. They are mainly linked to light industries and freight distribution where rapid movements of freight in small batches are the norm. Yet, with containerization, road transportation has become a crucial link in freight distribution.
b. Rail transportation and pipelines
Railways are composed of a traced path on which wheeled vehicles are bound. In light of recent technological developments, rail transportation also includes monorails and maglev. They have an average level of physical constraints and a low gradient is required, particularly for freight. Heavy industries are traditionally linked with rail transport systems, although containerization has improved the flexibility of rail transportation by linking it with road and maritime modes. Rail is by far the land transportation mode offering the highest capacity with a 23,000 tons fully loaded coal unit train being the heaviest load ever carried. Gauges, however, vary around the world, often challenging the integration of rail systems.
Pipeline routes are practically unlimited as they can be laid on land or underwater. Their purpose is to move liquids such as petroleum products over long distances in a cost-effective fashion. The longest gas pipeline links Alberta to Sarnia (Canada), which is 2,911 km in length. The longest oil pipeline is the Transiberian, extending over 9,344 km from the Russian arctic oilfields in eastern Siberia to Western Europe. Physical constraints are low and include the landscape and pergelisol in