Over 60 years ago, urban transportation was first subjected to systematic investigation, perhaps appropriately, in Detroit. The Detroit area study became the forerunner of transportation planning studies conducted in most large cities and countless other urban areas throughout the world. At the heart of this process were forecasts of personal travel and goods movement for evaluating alternative plans and policies. Significant planning decisions concerning transportation infrastructure investment and travel demand management policies, as well as major land use changes, have relied on the methods, techniques and ideas that emerged in this field over these six decades. The aim of this book is to describe the major developments in urban travel forecasting models and methods of analysis that were first established in the US and Canada in the 1950s and 1960s, transferred to the UK and other countries, and then extensively advanced and refined through research and practice. We trace the major technical and theoretical developments, with periodic hints of revolution, and their selective absorption into planning practice. We consider the ‘drivers of innovation’ over the years, in particular: (a) the increasing range of transportation policies considered; (b) the widening evaluation frameworks; (c) the means of analysing data; (d) burgeoning computing power; and (e) the role of simple intellectual curiosity.