The digitalisation of our cities is advancing. To make traffic in and transport to them smart as well, we need “smart roads”. But what does that mean? What additional functions will roads need when we are on the road with self-driving, connected cars in the future? Which digital possibilities will replace previous concepts? In any case, one thing is certain: the development of our means of transport will only go hand in hand with changes to our transport routes in the long term. We take a look at the future of the road.
It will probably be some time before we will be able to drive – or rather be driven – sustainably and autonomously on our roads as a whole. Preparing the infrastructure of our transport routes for this now is certainly a decisive factor. So-called smart roads promise a number of advantages even before the complete mobility shift is complete. In fact, the first test runs and many ideas have been underway worldwide for several years.
In 2018, a first pilot project with a smart road surface was launched in the US state of Colorado. The aim was to find out what positive effects a “data-collecting road” can have in accident prevention on a limited section of road.
The modular panels with sensors and fibre optic and radio technology built into the pavement enable the road to “sense” the cars driving on it and to compile the data obtained in this way on a dashboard. They inform the driver whether a car has left the lane or whether the road is still passable in the case of major weather conditions. Reactions can then be automated, such as sending an emergency call or disseminating a warning message.
But the other way is also conceivable: Intelligent roads could, for example, transmit impassable sections of road or danger spots directly to the autonomously driving vehicles so that they adjust their driving accordingly.
In the future, such warning functions with the help of smart technology would help to recognise unforeseeable dangers in good time in order to prevent accidents in advance. Colorado sees this advantage especially in view of the collisions often caused by truck traffic. It is therefore planned to equip many kilometres of highway in the state with technology in the coming decade that will allow information to be sent from the vehicles and, conversely, the technology will also deliver important information to the vehicles. Both will help to increase the safety of journeys and at the same time control transport routes more effectively. The basis for this is formed by so-called V2X communication systems: they ensure that vehicles exchange information with smart roads as well as with intelligent traffic lights or street poles.
Another recently launched pilot project focuses on intelligent traffic management: In the US city of Lenexa (Kansas), the extent to which an intelligent road surface can be used to avoid congestion and distribute loads is being examined. The vision associated with this is a big one: in the long term, this should provide the city with a networked infrastructure that functions effectively and efficiently, thus conserving resources and reducing the costs of municipal traffic control overall.
The basis here is also a road surface equipped with sensors and network devices through which information is transmitted. The panels are designed in such a way that they always automatically receive the respective updates – in other words, similar to what we know from our smartphones. If smart roads can be used to efficiently manage the flow of traffic, rush hour traffic jams may be a thing of the past in the future.
And in Germany? Here, too, the topic of smart streets is represented in various models of thought. Among others, with a particularly noteworthy approach. In a project funded by the Federal Ministry of Research and Education, science, industry and municipalities are working together on sustainable and climate-friendly concepts for urban and transport development. The Fraunhofer IGB is providing support in the area of urban water management.
The “Road of Tomorrow” aims to build resource-efficient roadways by installing new types of sensors and intelligent information technology. Instead of boring asphalt roads that prevent rainwater from getting into the ground, the new roads would open up possibilities for absorbing or transporting surface water, storing it and even treating it. According to the Fraunhofer Institute for Interfacial Engineering and Biotechnology, the resource water could be used more efficiently and thus more sustainably than before.
This would make it possible to use roads as living veins in the ecosystem in the future instead of brutally cutting up ecosystems with them. A beautiful thought.
Speaking of resources and sustainability: why not make use of the thousands of kilometres of road we have at our disposal to charge e-driven vehicles while driving? The first field tests on this idea are already underway. Inductive charging for e-vehicles by means of built-in modules on the roads would be all the more interesting if the energy passed on is then also obtained from the road itself.
This is also – unsurprisingly – a finding that is also already being tested. In the Netherlands, for example, photovoltaic roads have been tested since 2021. Meaningful results as to whether and to what extent this can be implemented and is efficient on a large scale in the long term are still pending.
All in all, there are a number of ideas on how and for what purpose roads could be used intelligently. Whether one or the other system will prevail remains to be seen. After all, all promising ideas must first pass the practical test of feasibility and financing. That can take time. And rightly so. Less than ten years ago, the first roads equipped with solar panels were hailed as THE solution to the energy crisis. In the meantime, many experts agree that this idea for generating, storing and supplying energy can be considered a failure. Too fragile, too expensive. And yet: new types of solar panels could lead to new results, as the project from the Netherlands mentioned above shows.
We are still – it seems – in the phase of “trial and error”. There are countless pilot projects, in the past five years alone. Only rarely are they associated with sustainable success stories.
This need not be surprising, because infrastructure as fundamental as the road network cannot be rebuilt and repurposed from one moment to the next. Moreover, every test project needs a certain size and complexity in order to produce real insights and thus come ever closer to practical requirements.
A showcase project in this sense within Europe could be the expansion of a 400-kilometre stretch of the Italian Autostrada del Mediterraneo into a Smart Road. A pioneering project launched in the USA, in which an entire traffic route ecosystem is to be created with the help of new technologies, also sounds promising: The Ray Highway already combines eight elementary ideas for smart roads. And this is exactly how the topic probably has to be approached in order to arrive at sustainable findings: in a joint effort of many participants, create a holistic system that allows indications of the best options.
One challenge with the complex topic of intelligent roads, however, is that there are many ideas in the room that do not quite mesh before the future is already a step further. Because, for example, the flying car is becoming a reality. Technologies are developing at an increasingly rapid pace. Small visions from today can be forgotten tomorrow. Or become standard. Who would have seriously believed 50 years ago that today we would organise our entire lives with the help of a single small device called a smartphone?
Text: Alexa Brandt