The Alps can be a source of union for the people from the valleys, but of separation for the people of the opposite plain. The early Romans were the first to build roads to overcome this divide in order to unite the empire. In late medieval times roads took on the role of the “centre” for communities with equal standing on each side of the valley. After a period of isolation shortly following the birth of the nation-state, the Alps regained their status as the linchpin of Europe. The real revolution occurred with the advent of the automobile: today certain areas are transportation corridors with a high influx of traffic.