Engineering Rome

Ancient Roman roads and their influence in modern road designs

By: Rowyn Lea

I. Introduction

Travel was difficult in the time of the Roman Empire. Before the Romans, there were no direct routes between different cities; if people wanted to travel, they made their own trail or followed dirt paths. Romans decided to make a better transportation system and developed the skills necessary to build efficient and durable roads. The techniques developed in the fourth century BC have impacted the way that roads are built to this day. Modern 21st century infrastructure is built with the acknowledgement of what was built in and around Rome thousands of years ago. This has caused modern Rome to hold on to old practices while also trying to move forward with modern technology.

II. History – Ancient Rome

The Roman Empire had specific types of roads and each type had a unique purpose that served the Empire. There were four main types of roads: public, military, local and private.

i. Public Roads

Public roads were both built and maintained by the Roman Empire. The biggest roads were the public roads as they were the most traveled, with carts full of goods and people traveling throughout the vast empire. The Via Appia, Figure 1, was the first road of this kind that was created by skilled builders and engineering. It was built in 312 BC and was the model for future roads construction. A major arterial road in Ostia Antica, Figure 2, was also built with big paving stones. As this road was in town, it has ruins of ancient shops alongside it. Ostia was Rome’s port city, it received large amounts of traded goods. Everything that traveled to Rome via the sea and ocean first had to stop in Ostia before continuing to Rome’s smaller port in the heart of the city.

Figure 1. Some of the larger paving stones used on the Via Appia, Rome’s first road of this kind (Photo by Rowyn Lea).

Figure 2. The main road in Ostia Antica (Photo by Rowyn Lea).

The government-funded public roads were not free to use. There were tolls on the roads; sometimes at bridges but often at the gates to a city (Crystalink). This would allow the Romans to tax the use of the road as well as the import and export of the goods that were being transported around the empire. Traveling citizens would also pay to be taken from one city to another as horses or carriages were a luxury that not everyone could afford (Crystalink).

In towns, there were pedestrian roads that were closed off to carts and horses so that people could mill about without needing to look out for danger from a fast-moving cart or animal. Porticos could also function in this role as they were covered walkways that often ran in front of shops or villas.

There were also roads that meshed pedestrian walkways with roads for carts, carriages, and animals. Pedestrians could walk on the outside of the faster moving horse and mule drawn traffic (Thompson 21). This was the first real use of the modern sidewalks that separated the different kinds of traffic that was seen in the city or edges of towns. Most public roads would have width for at least two carts to pass each other and would be covered with paving stones. Alongside, there would be a path of less durable rock or gravel that would allow pedestrians to safely walk without fear of crossing paths with other traffic. There was usually a height difference between the road and the path as well as occasional blocks that allowed for pedestrians to cross the road or mount a horse (Cartwright). This way there was a physical barrier that prevented the accidental cross of traffic.

Along with the military, the Roman road system was used by postmen to carry mail across the empire. Mail was carried by either public or private mail carriers. The public mail system was originally funded by Augustus and the private mail system was a network of slaves that could transport mail for a price (Crystalink). Regardless of how it traveled, mail took a long time to travel from one part of the empire to another. It could take weeks or months to for mail to get to different parts of the empire when mail was moved by horses or mules.

ii. Military Roads

Military roads were designed to be an efficient means to transport troops and other military supplies across the empire (Thompson 21). They were like public roads with their design and building methods but were constructed and usually maintained by the military. These roads were generally smaller than public roads and closed to civilian travel. The expanse of the Roman roads made it easy for the returning military to return with spoils from their conquest of a new land. Bringing carts upon carts back to Rome without the use of paved roads would be a difficult and long journey from the edges of the empire back to the center of it. Some of these triumphs can be seen on some of the triumphal arches.

iii. Local and Private Roads

Local and private roads were in and around cities, small towns, and individual houses. These roads were only used by a few locals and were not important to the whole of the Roman Empire. The government was not involved with building and maintenance so it was up to citizens to build, fund, and maintain local and private roads (Thompson 21). As most citizens were not trained with the engineering skills necessary to build high quality roads, they were usually dirt or gravel roads.

iv. Construction and Design of Roman Highways

Roman roads, public and military, were largely built with the same general technique throughout the empire (Thompson 21). Before a new road was built, extensive surveying was done around the area. Surveying helped to determine the best possible route to eliminate the most obstacles and make the straightest line when at all possible. The surveyors were usually well skilled men or soldiers who would consider valleys, mountains, swamps, forests, rivers, and towns when deciding on a new route (Cartwright). They would also try to have the road stop at larger towns when possible, but often bypassing smaller ones. This would allow for easier trade around the empire. Many of the roads were also named after the person who funded much of the construction of the road. For example, Via Appia is named as such after Appius Claudius Caecus who funded it (Cartwright).

The Via Appia is the first of the big Roman roads in which they started with a big trench that was dug and then they would lay a foundation to keep a smooth and level road. The foundation would be large rocks and sand, sometimes with wooden pillars driven into the solid ground to help support the road over marshes and swamps (Ancient). They would lay rock above the foundation and usually finished the road surface with large paving stones (Tom Rankin). There were curbs at the edges of the roads with the drainage ditches on the outside. These dimensions shown in the image were not universal across the empire, but show a rough estimate of the sheer size of the depth and width.

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Figure 3. A depiction of a cross section of a typical public Roman road.

Sometimes, in specific locations builders would use different kinds of surfaces, depending on the region and what kind of rock they had available to them. To prevent the roads from flooding, the roads were built higher than the surrounding ground, had drainage ditches on the sides of the roads, and a concave cross section so that the road would drain to the edges (Ancient). This allowed the roads to be used in all seasons as they would not be flooded during heavy rains.

Romans were good at finding solutions for geographical challenges that they faced when they were building new roads. When they faced a river or a mountain, it would be easier and possibly more economical to keep to a straight path and build a bridge or tunnel instead of going around. They would build their bridges with an arch design of either wood or stone supported by wooden pilings or stone piers if the crossing was too large to support a simple structure (Crystalinks).

Not all the roads that the Romans paved were new. In some cases, there was already a dirt or gravel path leading through the countryside. The Romans just dug the trenches to put in a foundation and paving stones on the top surface (White). The Romans tried to be conservative whenever possible, cases such as the Pont du Gard in modern day France is such an example. They combined an aqueduct and a bridge to cross the river at the same point using the same arched structure. Using the arcades of the aqueduct alongside the arches required of a river crossing allowed the government to save materials and use fewer skilled laborers, which conserved money and time. Since the road is so complex it would be tolled. The toll would help with the upkeep of the whole structure, which in this case would also benefit the aqueduct.

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Figure 4. The combined aqueduct and bridge structure of the Pont du Gard from the river valley (Photo by Rowyn Lea).

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Figure 5. On the Pont du Gard looking at the aqueduct and bridge surface (Photo by Rowyn Lea).

Roman roads needed to span the empire to help the emperor stay in control (Trueman). Romans built “roads [that] used bridges, tunnels, viaducts, and many other architectural and engineering tricks” to create as straight of roads as was physically possible (Cartwright). The first major Roman road, Via Appia, was started in 312 BC and went from Rome to Capua and later to Brundisium, an impressive 354 miles in length with a 56 mile straight section starting in Rome (Cartwright). Much of this road around Rome is still visible and is currently an active road. When bicycling down the Via Appia, its smooth paving stones have worn away into bumpy and difficult road to travel on. Vehicles that drive down it need to go exceedingly slow and would be a hazard to mopeds and motorcycles. Despite the poor condition by today’s standards it has certainly stood the test of time because it has been almost 2,330 years since construction started on the road.

Figure 6. A depiction of the major roads across the geographical modern Italy (Hopkins).

Figure 7. A depiction of the major roads across the entire Roman Empire at its peak. They allow easy travel around the entire Mediterranean Sea (Ancient).

v. Maintenance

Maintenance was of great importance to the ancient Romans. An effective network of roads needed to be constantly maintained. The government was responsible to fund maintenance and repairs of the public roads. Military roads were typically maintained by soldiers that were in the area and available to do the work. The soldiers had the necessary skills to create and maintain their roads (Thompson 21). This also provided good opportunity to keep soldiers busy and fit by continually doing labor when not attending to their military duties. If soldiers were busy, citizens were tasked with the maintenance. Necessary funding was raised by either a private individual or taxes collected (Crystalink). The taxes would be on the imports and exports of goods as well as the tolls to enter cities and cross bridges. There were mile markers placed occasionally along the roadside to show Roman miles to the destination as well as who oversaw maintenance for that section of road and what maintenance had been done on that section (Cartwright).

III. Modern Rome

i. Types of Roads

In Rome, there are numerous types of ways to get around the city. Vehicle roads, which carry busses, cars, small delivery trucks, motorcycles, and mopeds, are certainly the most prevalent to and reach virtually every part of the city. The biggest roads cutting through and around the heart of Rome are all nicely paved with asphalt. The smaller roads are usually cobblestone and are shared by pedestrians and vehicles. The bigger roads have sidewalks that are either raised on the edges of roads or are separated from the traffic with metal poles. The sidewalks are not always useful for pedestrians because motorcycles, mopeds, and occasionally cars will park on the sidewalks. As much of the city is covered in cobblestones, bicycling is not a very common occurrence. It is difficult to ride a bike over cobblestone and challenging to ride on the asphalt roads while competing for space with the faster vehicle traffic. There are several designated bike paths in the city, but they are hardly ever used because they do not go anywhere in particular and stop and start randomly. Although Rome is an easily walkable city, where most things are all relatively close together, vehicle traffic is immense.

In the inner city of Rome, vehicle traffic is limited to only people who have a permit for their vehicles and is enforced with cameras and license plate readers that send fines to anyone who violates the rules. This does mean that in certain parts of the city there should have less traffic and vehicles driving around, but after three weeks of observation I have not noticed any parts that have drastically fewer vehicles than others. The historical city center, where most of the tourists’ sites are, should be pedestrian friendly but is not because there are major vehicle roads that are vital to the well being of Rome.

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Figure 8. A street sign indicating a pedestrian only and non-pedestrian areas of the streets (Photo by Rowyn Lea).

Figure 9. A barrier to keep vehicles out of a piazza (Photo by Rowyn Lea).

ii. Issues Caused by Vehicles

In Rome, most designated pedestrian areas have vehicles driving around unless drastic measures are taken. Typical signs (Figure 8) that can be seen around the city showing where pedestrian areas are, but they do little to get cars and mopeds from driving anywhere they can fit. According to Adriano Morabito, Ideally, pedestrian areas are where people do not need to worry about looking out for cars driving by and mopeds speeding through, but that is not what usually happens. There are very few places in Rome that people need not be constantly on guard for fear of being hit by a motorized vehicle. This is one area that Rome struggles with, making sure that all traffic, from foot to tour bus, is safe when traveling in Rome. To help fix the problem, pedestrian bridges use chains and specially designed metal structures to allow bicycles and wheelchairs through but keep cars and mopeds off. Physical barriers which create curbs in the middle of a road (figure 9) are also built to keep cars out of piazzas. These are made with Travertine stones and cobblestones with a gap in the middle to allow wheelchairs and bicycles through but mopeds also will use this gap to drive through to where they want to go. The barriers do help some but not enough.

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Figure 10. Cars parked on a raised pedestrian sidewalk, prohibiting foot traffic from getting past (Photo by Rowyn Lea).

Theoretically, there should be a good solution to combining bikes, people, and vehicles safely so that everyone can get around the city. That is not the case as according to Tom Rankin, every year people get hit by cars and mopeds while crossing the roads in Rome . This is something that the Roman government should try to mediate, but is difficult to monitor. Barriers are one of the most effective ways to keep cars out of certain areas and that is why they are used today. Most small roads have pedestrians milling about in the middle this helps keep the speed of vehicles lower when they drive through as they must slow down to avoid people, but this is also dangerous. Sometimes people and cars are only separated by a few inches. This is a challenge that even the best engineers will have a difficult time resolving.

iii. Asphalt and Cobblestone in Rome

Building new roads in and around Rome is a difficult thing to do. First, there are problems with the limited space. The streets of Rome must be built around buildings and ruins that are hundreds to thousands of years old. Also, building new roads means excavating and digging in new areas. This is very difficult in Rome because there are so many ancient artifacts buried under the soil. According to Adriano Morabito, it costs huge amounts of money and time to invest in the archeologists and tools necessary to make sure precious artifacts aren’t ruined by the construction of new roads. Usually this is a cost burden that public agencies are unwilling to take on. Instead, roads are just resurfaced to keep costs lower.

The roads in Rome are paved with two different materials. Most of the main vehicle roads in Rome are paved with asphalt or are transitioning towards asphalt. Vehicles have a smooth road to drive on and vehicles can drive at higher speeds. It also reduces road noise from the tires. The smaller side roads are typically made with cobblestones. Cobblestones have been a part of Rome’s history for hundreds of years. They were first placed in St. Peter’s Square and then spread to most of the other streets in Rome (Johnston). The rock used to make the stones are almost all local, volcanic rock from the areas around Rome. It is then brought into the city and chiseled into the correct shape. In order to properly lay the cobblestones, a level base is constructed. A worker can then pound the cobblestones into the ground and make sure the surrounding stones are level and closely packed together (Johnston). Although most of the cobblestones can be reused around the city, sometimes new ones need to be brought in when old ones get too destroyed.

Although cobblestones are a rough surface to bike or drive motorized vehicles on, it is great for drainage and maintenance. By using a sand base with cobblestones when it rains, it allows the water to drain through the road.

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Figure 12. The Piazza Venezia in front of the Victor Emmanuel Monument, a level and well-maintained cobblestone area. Heavily trafficked by all vehicle types (Photo by Rowyn Lea).

There are places in the city that have a mix of asphalt and cobblestones. This defeats the benefits of both types. The roadway is not smooth and the cobblestones are not easy to maintain and repair. There are a few different ways that this can be seen. First of all, on a cobble stone street with random patches of asphalt scattered around. The patches appear after there is maintenance underground for sewer, gas, or water. Instead of returning the removed cobblestones they will instead mix up a batch of asphalt and lay that down, often creating uneven edges where the asphalt meets the cobbles.

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Figure 13. A sloppy mix of asphalt and cobblestones. An inadequate foundation layer caused the unevenness, holes, and sinking. Only injury or a formal complaint will get this fixed (Photo by Rowyn Lea).

There are also numerous areas around Rome where cobblestones are paved over with asphalt. In a way, this could be a smart idea. The cobblestones, if they were laid correctly, would act as a good sturdy foundation for the asphalt to go on. It would also be cost efficient if the road was to be covered with asphalt by not tearing out the cobblestones but rather use them would save money. If the cobblestones were not well placed or have come loose over time, which is quite common when looking around piazzas and streets, it could lead to a short lifespan of the asphalt road.

The worst combination that I have seen is where cobblestones are the paving surface but instead of using sand as the base for the cobblestones to be pounded into it is asphalt. The benefit that this might have would be that cobbles might stay tightly packed for longer than if it was just sand. But, if they do come loose, it will be much harder to fix the road. It is a way of making the cobblestone road permanent. Unfortunately, the best part about cobblestones is that they can be moved at a moment’s notice.

Painted cobblestones easily get worn out due to vehicle tires and are thus an ineffective and inefficient way of creating safe guides for people to follow. Maintenance is a never-ending task.

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Figure 14. A cobblestone road with extremely worn paint (Photo by Rowyn Lea).

A benefit of using cobblestone for is that the crosswalk can be made as a part of the road. By using white cobblestones instead of black ones, the white stripes of the crosswalk stay obvious for as long as the cobbles stay in the road. This means that the maintenance for properly maintaining the crosswalk will be minimal, thus saving time and money for the local government.

Figure 15. A cobblestone road that uses white cobblestones instead of paint to mark a crosswalk (Photo by Rowyn Lea).

The critics to cobblestones are mainly local Romans. According to Tom Rankin, the people who drive are people who are against the continued use of cobblestones for paving in the city. The cobbles make too much noise and are too rough for comfortable travel in a vehicle. Each little cobblestone is also very smooth and once it rains they become quite slick, even to walk on.

Crews working under the road surface do not have to cut through the ground but instead just pull out the cobblestones and dig out the underlying sand. It is also much easier to repair damages to the road surface. Road crews can pull out damaged and broken stones and replace them with new ones. In order to do repair work under the road, workers pull up the cobblestones, set them aside, and then excavate the necessary dirt. When they are done, they fill in the dirt, level it, and relay the removed cobbles.

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Figure 16. Repair work on pipes underneath a cobblestone sidewalk (Photo by Rowyn Lea).

Working under cobblestones is opposed to the difficulty with working under asphalt. In order to excavate the necessary area, they needed to break up the pavement, scoop it out, carry it away, and then dig into the underlying dirt. When they are done with their fix, they will have to fill in the hole, level it, and then carry in asphalt and a compacter to flatten the asphalt.

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Figure 17. Repairing pipes under an asphalt sidewalk, a lot of work for this small section (Photo by Rowyn Lea).

Pot holes and small sink holes can be seen all around Rome and can open at any time. It is difficult and expensive to go around Rome continually fixing small holes that open in asphalt due to all the heavy machinery required. After speaking with Adriano Morabito, he mentioned that sink holes are a common occurrence in Rome. Underneath the current Rome is an older version from the past. New roads go right over the top of ancient houses and shops. When continual traffic or heavy traffic in a new area drives over these underground voids, they become visible. This is a problem that will be present in Rome for the foreseeable future as it is impossible to know what is underneath the version of Rome that stands today.

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Figure 18. A crew repaving a section of the Via Del Circo Massimo (Photo by Rowyn Lea).

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Figure 19. Crisp new crosswalk stripes on smooth asphalt at Lung. D. Vallati. It won’t be long until people need to fix new potholes and repaint the crosswalk (Photo by Rowyn Lea).

IV. How Roman Engineering has Survived

In ancient Rome, engineers were the masterminds that were able to create the expansive and astonishing Roman Empire. They created the tools necessary for them to complete their impressive work. They built things to last, and even though much of the construction documentation was lost over the millennia, the physical structures have lasted. By investigating the roads that are left over from the empire, it is almost as good as reading through documentation.

The Romans were the first civilization to build roads with a consistent method. Other civilizations had built roads similar to the Romans but nobody created roads on such a large scale. To be able to build high quality roads quickly at all ends of the empire was astonishing.

Surveying thoroughly and laying proper foundations was the key to having straight and strong roads. Surveying and foundation laying techniques are still in use today. Extensive research goes into looking at different foundation designs for roads. Romans knew that they could use different foundation styles in different locations, depending on the road use and the soil quality in the surrounding environment. Engineers and researchers follow these rules. Roadway foundations are dependent upon environment and roadway use.

Figure 20. An active Travertine quarry an hour away from Rome (Photo by Rowyn Lea).

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Figure 21. A new sidewalk construction made with travertine stone and concrete foundation (Photo by Rowyn Lea).

Travertine is a local stone that is found all around Rome and was used by the Romans for numerous big projects such as the Colosseum and triumphal arches. It is still used to this day, there are numerous active quarries near Rome. Figure 20 is a family owned quarry that I was able to see and experience first hand. In roads, it usually ends up as curb stones that define the edges of sidewalks. It is astonishing that the same type of rock can be used to build new projects for over 2,000 years.

V. Conclusion

The general uses of roads have stayed the same throughout the ages. Roads have always been a way of getting around and moving goods in order to trade, buy, and sell. The Roman public roads were able to achieve this through masterful engineering, planning, and materials. The ingenuity and engineering that went into the designing and building of the roads is what made the Romans so great at it and why they set the example for all future civilizations.

Modern Rome, could use the ancient Romans as inspiration to make the road system better and continue to improve the quality of the roads that are made today. Unfortunately, that does not seem to be the case. The roads that are built today need constant major maintenance to keep the city moving. The Roman Empire also needed to do maintenance, but it was not nearly as frequently as they wanted to build roads that didn’t require maintenance. The roads that are around Rome today are rarely smooth and need patches to fix and cover up pot holes and sink holes. Even roadway foundations are only built with a certain lifetime in mind. In today’s age we do not build things to outlast us.

VI. References

“Ancient Rome Culture.” Roman Roads,
Cartwright, Mark. “Roman Roads.” Ancient History Encyclopedia, 17 Sept. 2014,
“Crystalinks.” Roads in Ancient Rome – Crystalinks,
Hopkins – May 18, 2012 12:17 pm UTC, Curt. “Travel across the Roman Empire in Real Time with ORBIS.” Ars Technica, 18 May 2012,
Johnston, Alan. “The Uneven Charm of Rome’s Cobblestones.” BBC News, BBC, 24 May 2013,
Thompson, Logan. “Roman Roads.” History Today, vol. 47, no. 2, Feb. 1997, p. 21.
Trueman, C N. “Roman Roads.” History Learning Site, 16 Aug. 2016,
White, Chris. “The Beautiful Network of Ancient Roman Roads.” Atlas Obscura, 19 June 2015,

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