The research reported in this monograph follows on directly from the findings that were reported in BAR 492, in which, among many other discoveries, the author recognised that the courses of both Roman Dere Street and Hadrians Wall had been underpinned by frameworks of long-distance alignments. Stimulated by the detection of several more of these alignments across northern England by another researcher, Robert Entwistle, the author, who is a chartered engineer as well as an archaeologist, seeks to examine why, how, and when such long-distance alignments may have been laid out. Consideration is then given to the processes by which some of these alignments seem subsequently to have been adopted to help set out the courses of Roman roads. These processes are shown, at times, to have been far from straightforward, and this appears to offer an explanation for many of the minor divergences that Roman roads, as built, take from such alignments in practice. The courses of four well-known Roman roads in NorthernEngland are then examined in detail to diagnose the processes by which they are likely to have been planned and laid out. These roads are the Western Main Road from Manchester northwards through the Lune Gorge, the Maiden Way, the network of cross-country roads from Kirkham to Aldborough, and the Devils Causeway.