Bottom view of cars crossing the cobblestone street. Cobblestones are typically either set in sand or similar material, or are bound together with mortar. Paving with cobblestones allows a road to be heavily used all year long. It prevents the build-up of ruts often found in dirt roads. It has the additional advantage of not getting muddy in wet weather or dusty in dry weather. The fact that carriage wheels, horse hooves and even modern automobiles make a lot of noise when rolling over cobblestone paving might be thought a disadvantage, but it has the advantage of warning pedestrians of their approach.