Infrastructure and Urban Landscape

High-level rail infrastructure is essential for sustainable passenger and freight transport. While track systems such as those for trams or light rail systems can often be easily integrated into the urban space, high-level railway lines are generally planned without crossings. However, the routing of subway and suburban railway lines, as well as long-distance and freight lines, follows a distinct logic, which often conflicts with the urban spaces through which they pass. Particularly in densely built-up and small-structured urban areas, the railway infrastructure often acts as a significant barrier.

In order to mitigate the effects of barriers, measures such as the construction of passageways and integrated structures beneath elevated railway lines, the development of enclosures for at-grade tracks, the construction of bridges, and the covering of low-lying railway lines have been employed. Furthermore, these measures present opportunities for the utilization of areas beneath, alongside, and above railway facilities in a variety of ways, including the creation of public spaces, the connection of path networks, and the promotion of natural connections.

Vienna, with its historically evolved railway infrastructure, serves as a key area of investigation. The aim of this analysis is to ascertain which planning processes and design principles enable the (re)integration of railway lines and track areas into their urban context. The spatial integration of Vienna's railway systems exhibits significant variations. The urban railway arches designed by Otto Wagner are characterized by the combination of transport and urban planning considerations, and are used in a variety of ways. These arches are notable for their high urban planning quality, yet problem zones or underused areas are often found along newer lines.

The emphasis on the provision of affordable housing exerts a dominant influence on Vienna's urban planning, extending even to the scientific focus. Consequently, the construction of housing frequently comes into conflict with high-ranking infrastructure, as evidenced by the abandonment of some of Vienna's large stations, such as the Nord-, Nordwest- and Südbahnhof, in favour of new residential districts. Rather than incorporating the existing infrastructure and its associated uses into new plans, measures are being taken to dismantle railway sidings, close freight stations, and relocate stabling facilities to the periphery of the city. This development is partly driven by the interests of infrastructure companies.

In order to fulfil the task of running trains with as little disruption as possible, isolated train paths are the most efficient option. Integrated spatial concepts or more intensive structural utilization of their properties would make operations more difficult and therefore seem unattractive from the operator's point of view. However, there is also a need to reduce land usage, strengthen the qualities of the existing city and promote acceptance of the rail infrastructure as an essential component of the mobility transition.

The dissertation places significant focus on the necessity of an interdisciplinary planning perspective to achieve more effective integration of urban and infrastructure development. By integrating spatial analyses, case studies and design principles, it is expected to contribute to the advancement of the discourse on spatial layering along, above or below railway infrastructures as an urban development model.