This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book describes the design and construction of the first prototype version of an integrated transportation and land–use model package. It also describes chronicle the development of theory and the implementation of subsequent practical improvements to the model package. The book explores the transportation component is the focus of attention and discusses the development of models of intraurban employment location is taken up. It describes the theory and development of the residence location model used in later versions of the integrated model system. The book also describes a series of verification experiments for the residence–location models. It presents an entire new series of policy analyses with the modified version of the integrated model system. The book also discusses a potpourri of topics for further theoretical development and application.