 Though parts of Europe still had remnants of Roman roads built before the collapse of the Roman Empire, most had long fallen into disrepair.Because of the necessity to ride long distances over uncertain roads, smooth-gaited horses were preferred, and most ordinary riding horses were of greater value if they could do one of the smooth but ground-covering four-beat gaits collectively known as an "amble" rather than the more jarring trot.Mule trains, for land travel, and barges, for river and canal travel, were the most common form of long-distance haulage, although wheeled horse-drawn vehicles were used for shorter journeys.