Motorways are much more than traffic arteries: they are symbols for freedom, global interconnection, and economic dynamism. They also act as indicators of the local economy and other site factors, reflecting on the attractiveness of entire regions. Moreover, their use by millions of drivers mirrors the level of individual prosperity in a country.
When it comes to building motorways, China is second to none. Since the political opening of the country in the early 1970s, the Middle Kingdom has connected its provinces with a network of highways that now spans 160,000 kilometres, with about 8,000 kilometres being added every year. By comparison, Germany's motorway network has grown by 2,000 kilometres since 1995. But when it comes to expanding its transport network, China is not only fast – it is also highly innovative. They are now building “electric roads”, sections of motorway with wireless charging systems for electric vehicles. These will change the way freight is transported, eliminating the need for overhead power lines and heavy batteries. “China has invested a huge amount of money in developing its transport system and, as a rapidly growing industrialised nation, is making faster progress than other countries,” says Kevin Riehl of ETH Zurich, who conducts research at the Institute for Transport Planning and Systems.
“Alongside the US, China has played a key role in driving the technological development of intelligent transport systems and mobility services,” Riehl continues. In fact, Chinese tech giants Baidu, Alibaba, and Tencent are leading the way in digital transport services. With their navigation apps, China is equipping domestic vehicles to make them connected and intelligent.
“China has invested a huge amount of money in developing its transport system and, as a rapidly growing industrialised nation, is making faster progress than other countries.”
Every car becomes a sensor
At around 79,000 kilometres, the US Interstate Highway system is the second largest motorway system in the world. Spain, Germany, and France follow with 17,600, 13,200, and 11,000 kilometres respectively. Canada, Japan, Italy, Mexico, and South Korea complete the top ten. In all these countries, modern traffic management is a top priority to avoid congestion. “One thing we know today is that more roads lead to more congestion and are therefore not the answer. What we need are intelligent traffic systems in which every vehicle becomes a sensor. Vehicles will exchange information with each other and so can react better to accidents, jams, or heavy traffic,” says Riehl. Motorways also play a key role in autonomous driving: in addition to innovations for vehicles, the motorway itself is becoming more intelligent thanks to integrated technologies such as sensors in the crash barriers and road surface. Photovoltaic road surfaces are also being used to generate energy for street lighting and electric vehicles. However, due to the high investment costs, this technology is currently only being used on trial sections. Wireless charging allows vehicles to load up on battery power while driving. Heating systems in the road surface melt snow and ice, while dynamic road markings adapt to traffic conditions.
The intelligent motorway
In Germany, innovations such as inductive charging are being tested on sites such as the duraBAst “Research – Develop – Investigation” testing site. “Intelligent motorways will not only improve safety, but also increase traffic efficiency and reduce environmental pollution. Digitalisation plays a central role, for example through real-time data analysis and intelligent traffic management systems,” explains Prof. Gerd Riegelhuth, Head of Traffic Management, Operations and Transport at the German national Autobahn GmbH.
He also points out that while the main focus in Germany in the coming years will be on the maintenance and renewal of dilapidated bridges and motorway sections, it will also be necessary to invest in the digitalisation of motorways, for example to pave the way for autonomous driving. With more than 13,000 motorway overpasses, these upgrades will be an enormous challenge.
In any case, German motorways in particular are subject to enormous wear and tear because –as a transit country in the centre of Europe– most goods pass through here. In 2023, the Autobahn saw a total of 40 billion tonne-kilometres of truck traffic. At peak times, some 1.5 million heavy goods vehicles are travelling on German motorways at the same time.
“Intelligent motorways will not only improve safety, but also increase traffic efficiency and reduce environmental pollution. Digitalisation plays a central role, for example through real-time data analysis and intelligent traffic management systems.”
Singing roads and noise-cancelling concrete
Drivers on the A12 motorway from Frankfurt an der Oder to Berlin have already experienced the effect of so-called ‘whispering concrete’. Research has been going on for decades and the material has been improved. It is noticeably quieter in the car because the material has been engineered to reduce traffic noise. But to keep drivers' attention on particularly monotonous stretches of road, there are now also ‘singing roads’: When a car drives over it, the road surface generates vibrations that are transmitted through the wheels into the cabin in the form of musical tones. The vibrations are generated by grooves, rumble strips or marker buttons. Musical roads can be found in Denmark, Japan, the USA, China, and the Netherlands. And while they may look like a gimmick, they actually represent a whole new way of tackling the challenges of traffic.
Advances in materials science continue to offer new approaches to reducing resource consumption and environmental impact. According to Fortune Business Insight, the global ready-mix concrete market will be a $920 billion industry by 2023. By 2032, it is expected to be worth more than $2,000 billion.
Recycled materials such as asphalt and concrete reduce the need for raw materials and minimise waste. High-performance concrete and asphalt offer greater durability and resistance to weather and traffic, designed to last 100 years. Self-healing concrete automatically “repairs” cracks when exposed to sunlight, while nanomaterials such as nanosilica increase the mechanical strength of the motorway. The use of recycled materials is already standard in Europe and North America, while around the world, new technologies are being tested.
Financing and maintenance
Motorways are increasingly being financed through public-private partnerships. These models speed up project realisation and improve the use of resources. Many countries have tolling systems that help finance new motorways, though charges vary from country to country.
Tolls are also charged on motorways in many European countries, such as Austria, Switzerland, and Poland, while the Interstate Highway System in the US is funded by taxes. Maintenance costs are another important factor: modern materials and technologies can save costs in the long term, but require high initial investments. Highways play an important role in infrastructure development worldwide. The US is modernising its interstate highway system, while Europe is focusing on sustainability and digitalisation. In Southeast Asia, countries such as Vietnam and Thailand are expanding their highway networks to facilitate trade and mobility. India is building an average of 37 kilometres of motorway per day. This shows that the development of mobility continues, and we are far from reaching the end of the road.
