From 1964 until now, during regular flights, the CIRA of Bruxelles has carried on research in depth of the Roman road system in present Belgium. The number of roads and other ways and of fragments detected stretch chronologically from Antiquity to modern times. A selection of aerial photographies, where the fragmentary remains no longer correspond to the recent land patterns, has been made to rediscover the network of the ancient road system, in a major part wiped out by erosion. An interdisciplinary detection, which associates aerial research with methods of soil prospection, has allowed a precise knowledge of several Roman roads crossings and of their physical and anthropological environment.