The Roman road network in the north links the tribal capitals of the region north of Paris with the ports on the Channel and with the Rhine frontier.

Arras, Therouanne, Cassel, Cambrai and Bavay are the main road centres. Along the roads are found many place names recalling their presence. These can mark the line of the road even when all surface traces have vanished.

Roads are often marked by being used as community or estate boundaries. Tracing roads north of the Canche and in the Pas-de-Calais is difficult in the hilly country and very difficult in those areas flooded by the transgression of the sea around Dunkirk in the second century.