Balsa-Barreiro, José, Lukas Ambühl, Monica Menendez, and Rubén C. Lois-González. 2018. “Assessment of time-varying accessibility and territorial cohesion using Time Distorted Maps: a case study based on public transport systems in the region of Galicia, Spain.” Poster presented at the 97th Annual Meeting Transportation Research Board, Washington (USA), Jan 07-11.
The second half of the 20th century has led to an accelerated change in the economies and societies around the world. In the western countries, the focus on tertiary activities in urban areas increased the levels of mobility. This has also been observed in developing countries, where these changes take place at an even higher rate. From a worldwide perspective, the connection of market economies at global scales has increased the movement of people and goods exponentially.
Transport infrastructures are the backbone to any territory, they can reduce (or not) transport costs, and offer competitive advantages to nearby areas. Their spatial layout, design, development and management depend mainly on social and institutional concepts, which within the European Union (EU) reinforce the economic and social cohesion between the different regions.
The development and expansion of terrestrial transport infrastructures depends on the territory and human dynamics. In fact, since the second half of the 20th century, transport of passengers and goods has been clearly affected by the concentration of people in urban areas, the structural transformation of economics oriented to the services sector, and the democratization of the private car, among others. These factors as a whole have led to an exponential increase in mobility rates.
A classical idea of transport infrastructures as a system for generating wealth exists, which has led many authors to establish a binomial relationship between transport and development. Some economists argue that better infrastructures can reduce transport costs and increase productivity and competitiveness, because of the reduction of distances between raw materials and market, the two main actors of the economic system. In the short term, the construction of transport infrastructures can generate new jobs, while in the medium and long term it can increase the accessibility, the economic competitiveness and the employment levels, while it can also lead to further increases on demand. These perspectives were considered by the EU when implementing the TEN-T (Trans-European Transport Network).
A simple and effective way for evaluating, at least partially, the level of territorial cohesion and the equality of travel opportunities is to assess the accessibility. This term refers to the ability to reach desired goods, services, activities and destinations, which is the ultimate goal of most transportation forms. Transport infrastructures can determine the degree of accessibility to a large extent, although it is not the only determining factor. As a matter of fact, it is relatively difficult to measure the accessibility, as it can be affected by many factors, which are based on time, money, discomfort and risk, among others. Thus, a significant number of studies have focused on how to measure the accessibility. The activity-based travel models and the integrated transportation/land use models are considered to be the methodologies most commonly used. Moreover, most of the previous studies on territorial cohesion are focused on the reduction of imbalances caused by transport investments and have been applied on a large-scale, either supranational (as in the case of EU policies) or national scale only.
Geographical maps normally represent the transport infrastructures by using a geographical scale. This allows to measure the current distances between different points on a map. However, the actual distances (in terms of travel times) cannot be effectively estimated in an intuitive way. Actually, it remains unclear how to map such effect.