The articles in this volume summarise a number of recent developments in the railway field. Rapid results demand the use of modelling. The dynamic nature of the problems, together with the fact that the behaviour of the materials involved is often complex, mean that the models too are generally complex. Thorough validation against measurements is therefore highly recommended. Empirical studies will continue to play an important role in the approvals procedure for new structures and components.
The fact that many existing track structures are over-dimensioned is closely linked to the empirical approach to track design that has been followed for many years. An urgent need for optimisation techniques has thus arisen across the whole spectrum of railway engineering. This applies not only to the design process itself, but also to such issues as life cycle management and decision support 'or maintenance processes.
Increased speeds and axle loads are accompanied by increased risks. It therefore remains essential that we continue to refine the models and improve the experimental methods. In addition, there is a need to devote more attention to safety, standards and risk analysis.
Professor of Railway Engineering