Review 6_1

Road transportation is known to be a major consumer of space in comparison to other modes of transport. The construction of roads is characterized by physiographical constraints due to substantial additional costs that arise due to geographical features such as rivers, mountainous regions, valleys and rugged terrains (Kreowski, et. al, 2013).
Water transportation can broadly be divided into two categories namely inland water transport which operates in rivers, lakes and canals and oceanic transport which takes place in oceans and seas. Water transport is regarded as a slow mode of transport. However, they can be used to transport large amount of goods over a very long distance. Water transport can carry large tonnage at a very low variable cost which makes it the most favorable mode of transportation for large commodities. This mode of transportation is characterized by limited range of operation as it is confined to the presence of large water bodies. The water mode of transportation is characterized by high operational costs which is evident in the high terminal costs since the construction of infrastructures at the port are very expensive to build, maintain as well as improve. High Inventory costs also another characteristic of water transport.
Air transport is the recent mode of transport which is characterized by high speed and efficiency. This mode of transport is known to cover a very long distance within the shortest time possible. It is marked by high costs well as many travel regulations. The high cost is due to fuel, maintenance and labor charges. The construction and maintenance of airports is a very costly affair. This mode of transportation is used to transport light commodities which are delicate and perishable in nature. Air routes are usually unlimited and the constraints to air transport are the climatic conditions, aerial currents, fog and site (Hanson and Giuliano, 2004).
Rail transportation are