This, the first comprehensive study of an Irish turnpike road, represents a major contribution to Irish transport history. The early development of the main highway to the North from Dublin via Swords, Man-Of-War, Balbriggan and Drogheda is detailed and information regarding the legal and financial aspects of its operation as a turnpike road is given. The traffic on the road is studied in depth, and some of the distinguished travellers are named. In addition, the study also details the factors which influenced the fortunes of the road.