The french littoral has known several periods of traffic's development across the Channel. The Railway period, during the nineteenth century, drew the present map of main lines but the increase of road traffic has extended the front of competitions and asphyxiated the maladjusted lines. These deep transformations shape harbour installations to level the crossing's obstacles. Under these conditions, we don't wonder the economic consequences are small in local areas.Le littoral français a connu plusieurs phases de développement du trafic Trans-Manche. L'époque ferroviaire, au XIXe siècle, a dessiné la carte actuelle des principaux axes, mais l'affirmation du trafic routier a élargi le front des concurrences et asphyxié les lignes les moins ad...