Among other fields, the Roman Empire excelled in public works – its roads were the first ever. When you travel from Italy or the south of France to Spain, for example, some sections of the highway indicate that you are using the old Roman route. Its legacy is alive. Roman roads could also be said to be the first smart roads in that their construction techniques applied all the technology available then and the engineering concepts used were incredible for their time. The  Romans considered resistance to movement on gradients and longitudinal slope, never greater than the eight per cent over which animal-drawn carriages could transport cargo.

When necessary, the Romans levelled land to the millimetre, calculated according to the hardness of the mountain rock, and they used a collection of solid, smart materials to transport heavy items at speed. They also had accurate signage.

The road network played a vital role in linking territories, trade, the economy and communications over a large part of Europe and Asia.

Engineering has changed a lot since the Romans taught the world how to build infrastructure. But one reality hasn’t changed in the intervening years: the power of roads in economic development, social connectivity, and overall quality of life. Roads convert far into near, difficult into easier, and enables the impossible to happen.

It is important to consider the environmental impact during the planning and design phase of road projects.

Spanish multinational conglomerate Acciona has built over 5,000 km of highways, motorways and roads all over the world in recent years, creating grids of smart roads, which are increasingly innovative and sustainable, thanks to the advances in the technological revolution. It also carries out maintenance on a multitude of roads, including cleaning and clearing of scrub, drainage networks, culverts, underdrains and signage works.

Smart roads have some common characteristics, such as:

•  Circular economy for roads: Construction and maintenance of smart new roads is based on innovation and sustainability such as the use of recycled materials in road construction, which can help to reduce the demand for raw resources and minimise waste;

•  Road topography: The use of drones is essential in road construction today. Acciona uses this technology to generate 3D models of the land, monitor works and inspect the project and infrastructure aerially; and

•  Sensor-equipped highways: Smart roads will be able to gather and feedback increasing amounts of data about themselves and vehicles in order to optimise maintenance of the surface, and manage the road and its traffic more efficiently, as well as improving safety for drivers.

Smart roads: cocktail of technologies

Highways and roads are conceptualised on the screen of engineers at Acciona’s centres for technological innovation with the help of sophisticated software. Later, they are made real in the remotest of places thanks to the latest topography, 3D and 4D modelling, sensor systems, remotely operated machinery, drones, laser scanning and smart and sustainable materials. One example is composite materials, made up of resins and fibres so that combining them allows the creation of a new material whose properties are much greater than those that  each element can provide separately. Some of the benefits of composite materials include lightness, corrosion resistance, high mechanical resistance and electromagnetic transparency.

All sustainable materials are capable of self-repair and alerting where they are deteriorating. Solutions should pursue the application of the concept of circular economy and digitise processes to reduce construction delays and increase the reliability and safety of construction projects.

Another important task for its engineers is ensuring driver safety. Thanks to advances in innovation and sustainability, Acciona’s road projects not only reduce carbon dioxide (CO2) emissions but also the number of accidents on the roads.

Overall, road construction can have a wide range of impacts, and it is important to consider these impacts during the planning and design phase in order to minimise the damage and strive for sustainable construction. It is important to prioritise environmental studies in the development of road projects so that the impact on the surroundings and transport emissions can be minimised. Examples are designing routes that harmonise the speed of vehicles, avoiding driving in low gears and hard braking, toll points without barriers and using wireless communications so that cars don’t have to stop and queue – which is a major cause of pollution.

Technology and innovation are essential in building and maintaining smart, sustainable roads, which can cut CO2 emissions, reduce traffic, increase safety and improve communications and the economy.

And there is a wide choice of the latest technology that can be used to achieve fantastic roads including:

•  Drones: They perform mapping, inspections and maintenance from the air;

•  3D printing: This involves in-situ printing of various construction elements;

•  Remotely-operated machinery: These improve safety and accuracy of work;

•  Solar roads: They can supply electricity to the main grid and charge car batteries; 

•  Sensor-equipped highways: They alert, in real time, about the state of the road;

•  Self-healing asphalt: This can extend the lifespan of the road and reduce the need for frequent maintenance and repairs;

•  Luminescent cement and paint: They light the road at night-time without the need for an electrical supply;

•  Recycled plastic asphalt: It is sustainable, cheap, and durable;

•  Self-driving heavy construction vehicles;

•  Wireless toll stations without barriers: They cut CO2 emissions eliminating the need to stop cars;

•  Sensors for structures and corrosion: They monitor the state of infrastructure and anticipate faults.

In addition, planting of trees and shrubs can restore the environmental balance in the area.

I could say, with no doubt, that smart roads have emerged due to the urgent need to respond to challenges such as climate change and overpopulation. Such infrastructure is the product of a new era in which people and the planet are the priority.