In the Later Middle Ages the area of the Crown of Aragon (Catalonia, Aragon and Valencia) had a dense, well-linked road network of a largely functional nature. It was designed, built and maintained by means of collaboration between public authorities and private iniative. This communication system was made up by routes of different categories: major international axes, inter-regional routes, regional roads and local pathts. Since bridge building was a technically risky and financially complex undertaking throughout the Middle Ages, many rivers were crossed by means of fords o ferries. As this situation restricted wheelend traffic, the use of mule trains was favoured, even in the case of major international arteries. Road construction and maintenance was financed by means of tolls paid by users. In the final stages of the Medieval periode, increasing safety, the growing productivity of transport systems and gradually falling costs led to a substancial rise in the movement of both people and goods.