About the process of designing railway infrastructure
Nowadays the process of designing railway infrastructure is mostly seen as a sequential process. The sequential approach would appear to be obsolete, since it is lacking a consideration of customer needs. Therefore, it must be widened and parts of processes must be considered as what they are: sub-processes in a bigger picture. Since the sub-processes are dependent on each other they can be depicted as a cycle. This article presents the cycle of designing railway infrastructure. It has its focus on the German speaking area and aims to give an overview to the tasks and the relationships between sub-processes. It concludes seven subprocesses and eight relationships. It starts with the customer needs for transport which have only been considered indirectly and are generally not one of the primary concerns for designing railway infrastructure. After that a political process determines how to correspond with these customer needs. It includes several inputs like funding, general laws for railway, and the geographic constraints. From the complex political process originates a design target, which is translated into an operational concept. These operational concepts differ in Europe with different focuses on the primary target and an example is discussed as a guide for further development. The operational concepts are then further processed with common evaluation tools to create the bases of design for the infrastructure. There are feedback loops from the evaluation tools to reconsider certain constraints from former sub-processes. After the evaluation tools conclude that an infrastructure is feasible, the infrastructure will be constructed. Later, a specific t imetable is constructed on the basis of the infrastructure, which will then be used by customers to full-fill their needs.