As the Empire expanded, the administration will thus adapt the same scheme to the new provinces. At its peak, the main Roman road network would thus reach around 150,000 kilometres. Roman traders very quickly saw the interest of such axes. Unlike other Mediterranean civilizations who had based their commercial development almost solely on their ports, they will use their road network in parallel with their commercial fleet. This will promote trade with the interior of the continent and will be the source of their rapid commercial expansion. Entire regions will thus specialize and trade with each other (wines and oil in Hispania, cereals in Numidia, pottery and meat products (smoked, salted, etc.) in Gaul, for example).
The heyday of the network or the end of the Empire
From the 3rd century, the Roman world, well sheltered behind the limes, its fortified border, was gradually overwhelmed by peoples from the east:this was the start of the great invasions. Ostrogoths, Huns, Visigoths will thus follow one another on a road network of exceptional quality. This will therefore accelerate the progress of these groups. The Roman road, which was one of the keys to the expansion of the Empire, was thus one of those to its fall.