The history of roads is essentially the story of the travellers and commerce upon them. From the amber and silk of ancient days through troop movements and postal service in historic times on to the superhighways of present and future, Schreiber's chronicle of road building and usage wends its scholarly way. ""Good roads,"" he observes, ""are the product of strong government"". Among Persians, Greeks, Romans and Incas, for example, as behind the modern Iron Curtain, the governments that controlled roads were so strong that all major arteries were built by forced labor. Schreiber maps the saga of roads not only by sovereign subdivision but by the type of vehicle and the nature of public opinion. Railroads and water traffic mean little to him, but bridges, tunnels, and ancillary facilities are dutifully described. Cost, safety factors, and geopolitical aspects of roads in ancient and modern times make this a fairly comprehensive commercial history of the world. In describing efforts to uncover facts about roads of the past, fascinating archaeological premises come under study. Pioneering work leading up to contemporary cars, buses, jeeps and tractors is credited to men who foresaw not only the disasters and depredations of speeding, but the amazing prediction that soon ""a hundred million motor vehicles will be swarming over (the earth) like insects"". Superficially this is a dry record of labor and capital investment, but between the lines may be read the fabulous story of man's achievement.