How were the roads of ancient Roman built and what did they teach us?

The structure and dimensions of the most ancient network complex

“Omnes viae Romam ducunt” or All roads lead to Rome: this phrase summarises succinctly the intent of the Roman Empire. At the peak of its expansive phase, it had developed a road network to make it easy to travel to Rome from anywhere within the network.

This network built by the ancient Romans represents an extraordinary feat of engineering even to this day. It also reveals an acute understanding on the part of the Empire of the role and importance of a road network for military and economic purposes.

The road network built by the ancient Romans can still be used after serving the empire well for military, political and commercial purposes. It helped the Roman Empire impose its hegemony across the lands it conquered.

These ancient Roman roads calledpretorieor consolari contributed to the development of ancient Roman civilisation throughout its dominion. The Empire pursued infrastructure works up until the twilight of its hegemony, ensuring strategic links with sound and innovative construction methods from the point of view of engineering and architecture.

The roads of ancient Roman are a testimony to the civil engineering skills at the service of the Empire, enabling it to conquer lands, dominate peoples and defend its borders.

How ancient Roman roads were built

The method at the base of the construction of roads in the Roman Empire was rather complex. The first step was to define the edges and dig a deep trench. Inside this trench were placed four layers of various materials. The technical term via strata is the origin of the word road” or street in Italian: strada. The viae were the roads that connected Rome with other cities, while the those within urban centres were known as strate.

Our knowledge of the construction of roads by ancient Rome, usually for military then communication and commercial purposes, is thanks to literary testimony by writers like poets Publio Papinio Stazio or Livio. Archaeology has also helped:
 

  1. The first of the four “strata” or layers was the statumen, a base made up of blocks 30 centimetres high.
  2. The second layer was the ruderatio made of round stones mixed with lime.
  3. The third layer was the nucleus, gravel levelled with heavy rollers.
  4. The fourth layer was the pavimentum, big, hard, stone slabs that were virtually indestructible.

The curved surface of the completed road allowed for rain water to flow to the sides where channels would disperse it.

As for the measurements of these ancient Roman roads, the standard ranged between four and six metres in width. The bigger ones designed for the passage of two carriages were between 10 to 14 metres in width.

Sidewalks, or pavements, for pedestrians were beaten down earth between three and 10 metres wide. Where roads were heavily used, these sidewalks were used by pedestrians as well as horses.

The art of the construction of ancient Roman roads

The construction of roads during the time of ancient Rome also include bridges to cross streams or rivers. Many of these are still crossed today.

If a planned route met an obstacle like boulders or a mountainous terrain, tunnels were excavated by hand. So nothing ever came in the way of the construction of a road. And they were always straight.

Along the side of these roads were milestones, small columns that marked the distance in miles, the unit of measurement adopted by the ancient Romans, deriving from the “Miliario Aureo” or “Milliarium Aureum”, a marble column in gilded bronze erected inside the Roman Forum in 20 B.C. under Caesar Augustus. It represented the starting point for all the roads in the empire.

The names of the roads of ancient Rome

But what are the names of the main arteries of the road network of ancient Rome?
The “consulari”, or roads, owe their names to the consul who ordered their construction. In other cases, they were named after the purpose for which they were built. They all started from the Roman Forum near the Temple of Saturn.

From the end of the 4th Century B.C., the roads being built were numerous. Among the most important is the Appia, commissioned by the censor Appio Claudio Cieco for military purposes. Then there is Via Valeria, built at the behest of the consul Marco Valerio Massimo as an extension of Via Tiburtina that reached Adriatic. Another, Via Salaria, would lead to Via Flaminia, built by Gaius Flaminio Censor, connecting Rome to Rimini. The backbone of central Tyrrhenian Italy is Via Cassia, commissioned by the censor Caio Cassio Longino. It crosses all of Etruria. Via Aurelia, opened by the censor Caio Aurelio Cotta, carried traffic to the north along the west coast, reaching the site of the port city of Genoa.

Below is a list of the roads of ancient Rome still in existence and the respective connections:
 

  • Via Aurelia: from Rome to Luni
  • Via Cassia: from Rome to Massa
  • Via Flaminia: from Rome to Rimini
  • Via Salaria: from Rome to San Benedetto del Tronto
  • Via Tiburtina: from Rome to Pescara
  • Via Casilina: from Rome to Santa Maria Capua Vetere
  • Via Appia: from Rome to Brindisi