Traffic news on the radio could soon be a thing of the past. In the future, autonomous vehicles will communicate with one another, and traffic jams will be written off for good. But is this vision realistic? And what can we learn from ants?
Germany’s longest autobahn, the A7, is around 962 kilometers long – and is famous for its traffic jams. Roadwork signs and speed restrictions are a permanent fixture. And anyone setting off for an important meeting at the start of the vacation period should beware. Tune in to the traffic news and you’ll probably hear something like: “A7, Hamburg towards Hanover. Roadworks between Seevetal and the Walsrode intersection, congestion for ten kilometers.” Cue the stress hormones. But when cars become autonomous, this could soon be a thing of the past. Vehicles could drive along at a uniform speed, slotting smoothly into the free-flowing stream of traffic. It could spell the end for flashing headlights, tailgating and, above all, congestion and accidents.
In this future world, cars communicate with one another. They share traffic information with the vehicles behind them, and are guided by information from those up ahead. Algorithms calculate in real time the optimum speed for traffic to run smoothly, safely and without stress. Travelers can sit back and reach their destinations without nerve-wracking holdups. But is this vision of a congestion-free future at all realistic?
Today, traffic jams are a part of everyday life for road users. And academics have been studying them for years. In 2017 alone, for instance, Germany reported a total of 1.5 million kilometers of traffic jams. Every German citizen spent an average of 2.4 days stuck in traffic. If you were to line up all the cars caught up in traffic jams in a year, the giant tailback would circle the globe 38 times. But how do traffic jams form? Some of the causes are obvious: Bottlenecks from roadworks, accidents or trucks overtaking can quickly lead to delays. And the main problem is also usually obvious: The roads are simply too busy. There is only room for a limited number of cars on any one section of road. If the maximum capacity is exceeded, a traffic jam forms. Around 60 to 70 percent of all traffic jams arise in this way. Jams caused by the “butterfly effect” are more mystifying – a single driver can trigger a huge traffic jam and not even realise it. For instance, if the vehicle behind you is forced to brake, it unleashes a chain reaction: If the following vehicles are forced to reduce their speed to around 100 km/h, the vehicles behind them will have to reduce theirs to less than 100 km/h to avoid a collision. This wave effect can continue from one vehicle to the next until one driver is forced to stop altogether. This is the jam from nowhere, also known as a phantom traffic jam.
So, to achieve a future without congestion, we need to tackle the causes. Can we succeed? Congestion researcher Professor Michael Schreckenberg is skeptical. He holds the post of Professor of Physics of Transport and Traffic at Duisburg-Essen University and back in 1992, he and a colleague, Kai Nagel, published the Nagel-Schreckenberg Model, which formed the basis for modern congestion research. Nagel and Schreckenberg succeeded in producing a theoretical model using physics calculations to explain traffic phenomena like the phantom traffic jam. So what will happen if the roads are full of autonomous cars? Can we say good bye to traffic jams? Schreckenberg doesn’t think so. “Congestion is a universal phenomenon that occurs everywhere, not just on the roads,” he says. “It’s everywhere – from shoppers at supermarket checkouts to animals at waterholes and the blood cells in our veins.” But what if congestion becomes something we can calculate and predict, and cars are equipped with intelligent systems? “Even then there would be traffic jams,” says Schreckenberg. “Jams always occur when there are too many cars on the same stretch of road. We might not have congestion on autobahns/motorways/freeways any more, where convoys of autonomous vehicles will roll from A to B like railroad trains. But then jams would occur at bottlenecks – entrance ramps, for instance, where cars would have to wait their turn to merge into the line of traffic.”
Jan Schöning is Head of Urban Development and Smart Cities at Siemens, and he’s a tad more optimistic. At a congress on cities of the future held in Stuttgart in 2017, Schöning said he could certainly imagine a future without traffic jams. Convenience, he said, was always the key factor when choosing a mode of transportation. In the future then, the aim should be to diversify convenience – to offer people alternative transportation services that would prompt them to change their habits. Schöning sees the solution in a mix of transportation – from bicycles and trains to car-sharing models and taxis. His ideas are supported by a recent simulation study published by Audi and conducted in collaboration with the Karlsruhe Institute of Technology and MobilityPartners, a consultancy firm in Munich. The study finds that, despite the growing population, traffic could decrease in the future, and connected cars could help eradicate congestion. Here too, however, a key factor is the availability of a combination of transportation services, such as car sharing. On the other hand, if transportation were to focus solely on connected cars, vehicle use would have to fall by 60 percent to reduce congestion. “The findings show that autonomous vehicles, transportation services and connected infrastructure can significantly reduce traffic jams and the space needed for roads,” says Melanie Goldmann, Head of Culture and Trends Communications at Audi. On their own then, autonomous and connected cars are not likely to bring an end to congestion. But they might succeed in combination with other transportation options.
There is another important point here, one on which the experts agree: Autonomous vehicles will make traffic safer. Even if the roads will not be completely free from traffic jams in the future, there will be far fewer accidents, which means accidents will be practically eliminated as a cause of congestion. At Continental too, engineers are working intensively on the safe car of the future. The car’s “sixth sense”, or swarm intelligence, will soon be a reality. Work is currently in progress on a system that will provide cars with accurate information about the traffic situation and share it with other road users. Cars will know what’s happening round a corner before they get there. By 2022, the aim is to develop the Continental site in Frankfurt-Rödelheim into a competence centre for safe, assisted and autonomous driving. Over 100 million euros have been earmarked for the development and 200 new jobs will be created in research and development alone. “In Frankfurt we are working on challenges and solutions for future mobility,” says Frank Jourdan, a member of the Executive Board of Continental AG and Head of the Chassis & Safety division. “By expanding this site, we are securing and strengthening our position as an innovative and forward-looking company.” And there have already been several success stories. At the moment, around 90 percent of all accidents are caused by human error, which is why autonomous vehicles are an important step on the way to Vision Zero – roads without fatalities, injuries or accidents. Continental’s Cruising Chauffeur system can take over from the driver on motorways. Drivers can choose between partial automation – where they still have to monitor the system – and a highly automated option, which will be available in the near future.
However, there is already a road between Northern Italy and Spain’s Atlantic coast that is nearly 6,000 kilometers long and on which there are never any traffic jams. No honking, no jostling for space, no risky overtaking, no speed limits and no warning signs. This is the road used by Linepithema humile. No, it’s not a new make of electric car or autonomous vehicle. Linepithema humile is an Argentine ant. Billions of ants travel this road – attracting the attention of not only naturalists but congestion experts as well because they demonstrate congestion-free mass mobility. “Ants are cooperative,” says congestion researcher Schreckenberg. “Their own progress is no more important to them than the general flow of traffic.” The insects travel at the same speed and in small convoys. And their cooperative behavior shows that congestion-free traffic can work – and maybe even that the key to success is not just about future technology and flexible modes of transportation. Cooperative traffic management could hold the answer.