Introduction

This introduction presents an overview of key concepts discussed in the subsequent chapters of this book. The book focuses on a major research project which set out to examine one particular policy domain, transport, in order to examine how discursive and institutional structures within government influence the achievement of sustainability targets. A 'sustainable' transport system means one that meets a variety of goals other than simple mobility. The transport vision grew within the shell of free market economics, which in turn emerged from the powers that shaped the eighteenth century philosophy of the Enlightenment. The 'discourse network' is a concept used to explain the interconnectedness of ideas, decision-makers and their mental models of reality: what is 'important', what 'the problem' is, and how to go about solving it. For example, existing transport policy remains essentially unchanged so long as key actors support it.