In the last issue of the magazine “Quarries and Mining”, in the article “Where macadam came from” in the paragraph entitled “A Little Bit of History – Romans”, I briefly addressed the topic of Roman roads.
The Romans had high demands on the quality construction of the communication network and their regular maintenance, as the roads were of strategic importance. Just for the sake of interest, I would like to add that if there was no insurmountable obstacle during the construction of the road, the road always led to the destination in the shortest direction. Therefore, they are practically direct. This may be the beginning of what we now know from fairy tales as “… over the mountains, over the vales, over the rivers and over the forests…”. And one more note is worth mentioning that any intentional damage to the road was mercilessly punished by death.
Road construction technology
The construction of Roman roads was similar to that of the modern ones. The road consisted of three layers: the base, the supporting layer and the surface.
The Romans adopted the road construction technique from the Etruscan, and further improved it. The terrain was first cleared of vegetation and levelled and excavated. Water ditches were built along the road and the road itself was profiled so that water would be drained from its surface. In the case of road construction through water-soaked terrain, gratings made of wooden poles were placed at the bottom, fixed to the ground by hammered stilts.
The construction of the road consisted of several layers. A layer of mortar-bonded stones was placed in the excavated bed. The second layer of smaller stones, also connected with mortar, was placed on the thus prepared substrate, and on top of that some gravel with mortar. On the very surface, the road was levelled with a layer of gravel mixed with sand. Instead of mortar volcanic ash (pozzolana) was also used. In later times, the surface of roads was paved with flat stones.