Transportation has been important in geographic study for hundreds of years. In the early days of geography explorers used known sailing routes to explore new areas and set up trading outposts. As the world's economy began to modernize and develop railway and maritime shipping became increasingly important and knowledge of foreign markets was essential. Today transportation capacity and efficiency is important so knowing the quickest way to move people and products is important and in turn understanding the geography of the regions in which these people and products are moving is vital.
Transportation geography is a very broad subject that looks at many different topics. For example transportation geography could possibly look at the link between the presence of a railroad in an area and the percentage of commuters using rail to get to work in a developed area. Social and environmental impacts of the creation of transportation modes are other topics within the discipline. Transportation geography also studies the constraints of movement across space. An example of this might be looking at how the shipment of goods varies at different times of the year due to weather conditions.
To gain a better understanding of transportation and its relationship to geography transportation geographers today study three important fields that relate to transportation: nodes, networks and demand. The following is a list of the three major branches of transportation geography:
1) Nodes are the beginning and end points for transportation between geographic areas. The Port of Los Angeles is an example of a node because it is the start and end for the shipment of goods to and from the United States. The presence of a node is important economically because it can aid in the development of a city due to jobs for example.
2) Transportation networks are the second major field in transportation geography and they represent the structure and organization of transportation infrastructure like roads or train lines through an area. Transportation networks connect the nodes and are significant because they can directly affect the capacity and efficiency of the movement of people and goods. For example a well developed train line would be an efficient transportation network to move people and goods from two nodes, say, from San Francisco to Los Angeles. It is up to transportation geographers to study the differences between two networks to most efficiently move items between nodes.
3) The third major field of transportation geography is demand. Demand is based on the public demand for different types of transportation. For example if commuters are in constant traffic congestion on a daily basis in a city, public demand might support the development of a transit system such as light rail to move them within the city or two and from the city and their home. Overall, transportation is a significant topic within geography because the world's economy depends on transportation. By studying how transportation relates to geography, researchers and geographers can gain a better understanding of why cities, transportation networks and the world's economy have developed the way they have.