Clustering of Infrastructure

Abstract

Bundling or converging infrastructure has been the leading principle for locating infrastructure since the mid seventies. It is assumed to offer certain advantages, such as a restriction of severance, consumption of free space and environmental hindrance. However, the concept of converging infrastructure has not always found its way to practise. In the Netherlands, less than 20 % of the railways and motorways are converged with any other type of major infrastructure. Even in new projects, a non-bundled location alternative is sometimes being preferred. A typical example is the High-Speed-Rail Project. This difference between theory and practise has been the direct inducement for this research. When converging infrastructure, there are a lot of physical construction possibilities. There are 4 criteria by which the construction type of the convergion can be described: (1) the types of infrastructure which are to be bundled, (2) the mutual position to each other, (3) the construction sequence and (4) te position of the bundle in its environment. Within each criterion, a number of discrete types can be derived. Although bundling has been an explicit principle in the planning and construction of new infrastructure since a few decades, infrastructure has been converged for several centuries. A convergion can originate from its own even when it has not been explicitly set out as a starting-point. This is also the case if several infrastructure lines are located using the same general location principles. If two or more lines ale located according to the principle of the direct or straigt line between two points, these lines will be converged automatically. This is essential, because the general location principles and conditions (internal, external and construction conditions) are converging conditions as well. Bundling infrastructure does not cause specific effects, but does have specific characteristics which can influence the extent of the effects. However it is not possible to define this extent exactly in general, because the environmental characteristics (which are variable) are an important factor as well. Nevertheless, converging infrastructure leads to a minor increase of environmental effects in comparison whith the construction of the new infrastructure line. On the other hand, converging infrastructure can cause a negative impact on the direct consumption of free space, the construction cost and flexibility of the infrastructure itself, and the safety aspects. These negative aspects can be solved by applying a suitable physical construction type. Generating of corridors is the only general effect of converging infrastructure. This effect should always be investigated by comparing it with the national policy.