In Roman Britain, the road between Londinium (London) and Noviogamus (Chichester) was completed with an error of less than one degree, a feat it has often been assumed was achieved without maps. However, little is known of when, how, and even why they were built. Davies uses archaeological evidence to examine what was built, and places these findings in historical context using sources from antiquity. What makes this study unique however is his use of expert knowledge from his work as a professional highway engineer to understand the significance of the roads. Davies analyses the possible methods the Romans used in order to achieve the durability and accuracy for which they are renowned, maintaining the extensive network in a working state the quality of which would not again be paralleled until the 19th century.