This chapter explores themes and connections that have emerged from this approach and its examination of the case studies. It examines aspects of the individual case studies together, demonstrating that we can only understand the traffic problem by looking across time, space, disciplines, and professions. The chapter draws together ideas about the relationships among traffic, capital, markets, and the state. It considers how much of what has been explored is particular to London and how much could apply elsewhere. The chapter argues that London's physical and historical geometry renders its traffic unique, but with powerful connections to other places that give the present account value as a model for thinking about complex urban infrastructures and their problems more generally. The chapter also presents some closing thoughts on the key concepts discussed in the preceding chapters of this book.