In order to represent, more or less faithfully, the Late Prehistoric sites (Bronze Age, Hallstatt, La Tène A) featured in a corpus derived from a major linear development, one needs to take into account not only the specificity of the topographical and cultural contexts concerned by these preventive operations, but also, given the low density of structures in these sites and the absence - in most cases - of ditches, the way data has been obtained, that is the procedures used to detect and identify the sites.
This is why the first part of this article emphasizes the evolution of the procedures used, from one intervention to another; the second part shows the main advances obtained, thanks to the major linear developments concerning certain eras and one region – North-western Picardy- for which little information was available before the commencement of these linear works.
One of these advances was the acquisition of a basis for the development of a chrono-cultural framework, but the main result was the reappraisal of the potential of the plateaus, as opposed to the valleys, these latter having been hitherto considered as prime settlement sites.

Traduction : Margaret & Jean-louis CADOUX