The development of instability, associated with road construction is the source of important problems, This situation appears to be related to three fundamental circumstances: A complex orography; an abundant rainfall and a large amount of tectonically disturbed sedimentary rocks. The development of unstable slopes depends on the combination of the rock massifs, their strength characteristics, structure, and precipitation- runoff relationship. Moreover, in coastal areas, there are a series of additional aspects which necessarily have to be taken into consideration: the particularly aggressive...