Each era has its own novelties and each knowledge was bequeathed to the next generations – all things that are still useful to us today or at least astonish us. And while some structures, such as Stonehenge and the pyramids in Egypt, for example, remain a mystery to this day, others have long since been figured out and serve modern construction methods as well. So, too, Roman road construction, something that did not exist before. We will show you the peculiarities that Roman roads have. How were they built?
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The Roman road improved the infrastructure
The whole Roman Empire was crossed by the Roman roads. Since previously there were only simple paths and unpaved roads, the Romans made it their business to develop road construction that would make it easier for legionaries in particular to get around. But of course, the roads were not only useful to them. It also made traveling easier for merchants. And Roman roads were innovative and unique for the time.
The peculiarities that characterized the road in ancient Rome
The network of roads was built with the help of technologies that were new for that time and had a scale unlike any other civilization. Although each road was built as straight as possible and changed its direction only in extreme cases, the road network itself crossed mountains, overcame depths through fills and even rocks were quarried by the Romans.
And to illustrate the extent: Roman roads reached a total length of 120 000 km, covering a whole 3 continents – a length equivalent to two world borders. In Europe they covered 90 000 km. All roads are recorded on the so-called Peutinger’s Table, a road map. Impressive, isn’t it? This also explains the saying “All roads lead to Rome”.
Other interesting features
We have already mentioned that Roman roads were straight wherever possible and even crossed more complicated terrains such as mountain ranges. But what else characterized the construction of Roman roads?
- How wide were Roman roads? The Roman road was typically 4 meters wide. Thus, it could comfortably accommodate two wagons or a troop of 6 men.
- The Romans cleared the forests around the Roman roads. This was done to avoid ambushes by enemies.
- The Romans avoided swampy areas and, if possible, mountains to protect the troops.
- The roads were sloped on both sides to allow water to drain away.
- While the roads outside the towns were covered with a final layer of gravel, the town roads were paved with stone slabs (stepping stones), which guaranteed dry feet for the pedestrians. Stone was expensive and was therefore used only in important areas (for example, in Rome large cobblestones).
- Out of town, there were so-called milestones at rather irregular intervals, which informed how far it was to the next town.
Roman roads – construction in layers
But not only the length and technology to extend the road network is impressive. The construction of the road itself also shows great progress in development, functionality and efficiency. How were Roman roads built?
As a base the natural ground
First, the ground was excavated to a depth of up to one meter. This was then leveled and compacted (tamped) to provide a stable base for the future road. Areas of subsidence were in turn stabilized with the help of supports. In some cases, workers also added a layer of sand or mortar if the compaction did not become sufficiently stable.
Old Roman roads subsequently present a layer of stones, usually 25 to 60 centimeters thick. The stones are the size of a fist, which helped drainage. Indeed, through the cracks and crevices, water could drain without damaging the structure of the road.
Rudus and Nucleus
Rudus is the next layer, which consisted of gravel or crushed stone, with the small stones having a size of about 5 centimeters. This layer was 20 centimeters thick and then passed into what is called nucleus, which is a concrete layer. This concrete was a mixture of cement, sand and gravel. This road layer could also contain clay.
Dorsum or agger viae
This was the last layer, characterized by its slight curvature, allowing rainwater to drain in both directions. This not only promised dry feet, but also prevented the water from seeping into the lower layers. This surface, as already mentioned, consisted of different materials such as stone or simply gravel, sand or earth, depending on the area.
Sometimes Roman roads also received raised footpaths and corner stones on either side.
Roman roads today
Some roads continued to be used even after the fall of the Roman Empire, and to this day, in many cases, they serve as the basis for the new roads. There are even sections where the roads are completely preserved in their original form. Some famous Roman roads are:
- Via Appia – from Rome to Brindisi; oldest traffic route.
- Via Claudia Augusta – from Veneto to Augsburg and through the Alps
- Via Militaris – from Belgrade via Sofia and Plovdiv to Istanbul (then Constantinople), i.e. the Bosporus
Roman roads in Germany include:
- Via Julia – from Augsburg to Salzburg
- Via Agrippa – from Trier to Cologne
- Roman road Trier-Neuss