Like pearls on a string
Traffic congestion is the natural enemy of the everyday motorist. Given that the level of personal traffic is set to increase even further, Volkswagen researchers and mobility experts are working on future remedies. Their aim: to improve traffic flow by using intelligent cars that can see, hear and speak.
The simulated scenario on the screen looks rather cute, with computer-animated cars driving around in a circle. Suddenly, a vehicle brakes for no apparent reason. This causes a chain reaction: the second and third cars in line also follow suit, and the entire circle keeps on slowing up until more and more cars are stationary for longer and longer periods of time. A simple yet forceful illustration of an everyday occurrence that frequently makes life a misery for millions of road users: traffic congestion.
Small cause, great effect. For Dr. Hans-Jürgen Stauss, head of the mobility organizational unit in the Volkswagen Group, the virtual set-up with an abruptly braking car is the starting point for research into a phenomenon that is visibly leading to chaos on the roads, and not only in densely populated urban areas. Congestion is a problem that affects all highly differentiated and networked systems: it is found on railway lines, on water (container handling), in the air, in telephone networks and on the Internet. And there is no shortage of apocalyptic prophecies – for instance, some experts predict an Internet-led breakdown in global data flows in the very near future.
BILLIONS OF EUROS OF DAMAGE TO THE ECONOMY
Even if the worst fears never come to pass, traffic congestion already incurs huge costs. For a start, it causes untold amounts of petrol to be wasted – and unnecessary emissions generated – by stationary vehicles. In addition, working time lost owing to traffic congestion also causes billions of euros of damage to the economy every year. And the substantial traffic growth predicted for Germany – Europe’s traffic hub – is giving further cause for concern. According to the acatech study “Mobility 2020 – Prospects for the Traffic of Tomorrow”, car and truck traffic is set to increase by 20 percent and 34 percent respectively over the next twelve years. Is our mobility society in danger of grinding to a halt on the roads? International experts are warning against scaremongering and an over-dramatization of the situation. For example, traffic researcher Dirk Helbing, Professor at the Swiss Federal Institute of Technology, Zurich, firmly believes that it is possible to counter this development. According to Helbing, it is vital to develop and introduce cooperative driving systems and to help road users to regulate the traffic themselves by means of decentralized control systems. Although this may sound rather abstract at first, its meaning becomes clearer on examining the main reasons for traffic congestion: 50 percent of traffic jams are attributable to road works and 30 percent to accidents. It is narrow stretches of road such as slip roads that can slow down the flow of traffic or even bring it to a standstill.
IN FUTURE, CARS WILL SEE AND HEAR
So what can – and must – be done? Mobility research in the Volkswagen Group takes a scientific yet solution-oriented approach. Dr. Hans-Jürgen Stauss and his team are well ahead of their time when they talk about the intelligent car of the future that can see, hear and speak. A number of driver assistance systems already in existence – such as Automatic Distance Regulation (ADR) – ensure that the right distance is kept between two cars. However, this is just the beginning. As of 2015 or so, there are plans to equip all Volkswagen Group vehicles with sensors that assess the driving environment and the traffic situation. In addition, they will be capable of communicating with other vehicles by sending and receiving signals, i.e. exchanging information about traffic flow and bottlenecks. Stauss outlines the shape of things to come: “The car will have a telematic horizon, meaning that it can see better and further than the driver – even around bends.” Drivers will then be able to respond appropriately to the shifting traffic environment. However, what happens if all road users take the same steps to avoid a traffic jam? Wouldn’t such collective behavior be enough to cause a substantial traffic jam of its own? The answer is no: this will be avoided as long as the flow of information is sufficiently individualized. For this, it is necessary to network the decentralized sensor technology with centralized traffic management centers. However, Stauss emphasizes that the necessary long-range traffic sensors still have serious shortcomings that could be overcome through data highways between vehicles and traffic centers.
The mobility expert envisages the dense yet flowing traffic columns of the future as pearls on a string. Not halting, but moving freely – thanks to an electronic control system that permits shorter distances between vehicles traveling at higher speeds. Naturally, drivers will continue to have full control of their cars in the future. However, when confronted with a traffic jam, drivers can sit back and let the technology do the work, as an invisible hand guides them securely through the bottleneck.
„Cooperative driving“
Prof. Helbing, with the increasing volume of traffic in Germany – the transit hub of Europe – road congestion is becoming a problem that is causing great economic damage. What can be done to remedy this?
DIRK HELBING: The central controlling concepts behind traffic management as we know it are approaching their limits. The new trend is towards cooperative driving systems which help road users to organize traffic themselves.
Exactly what does this involve?
As you know, we already have driver assistance systems, but these are mainly there to enhance our comfort and safety. In future, the distance between vehicles and the speed at which they travel will be regulated at critical congestion points – such as roadworks or motorway junctions – by radar sensors on cars, which will have a positive effect on the overall flow of traffic. By using this kind of automated driving, we can stabilize traffic flows and increase capacity.
So traffic density is not the problem in itself?
Traffic density only becomes a problem when traffic comes to a standstill. A growing number of vehicles on the roads does not necessarily lead to congestion. It’s a question of keeping the traffic flowing.
Do we need additional motorways, or at least more multi-lane roads?
It would certainly make sense to provide motorists with extra lanes on certain routes. However, particularly in view of the need to preserve our environment, our priority should focus on further developing systems that facilitate cooperative driving. There would be much to gain from this.
„Interaction between man and technology“
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There is no quick-fix solution to the traffic congestion problem. Dr. Hans-Jürgen Stauss, head of the mobility organizational unit in the Volkswagen Group, makes the case for differentiated solutions.
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Dr. Stauss, are congested roads an unavoidable consequence of the growing mobility requirements brought about by modern business and lifestyles – a consequence that we must simply accept?
DR. STAUSS: Yes and no. It is certainly true that congestion goes hand in hand with densely populated societies and that it can never be counteracted completely. This not only affects personal transport on the roads, but also user traffic on the Internet, for instance. Congestion is caused by the increasingly fast and networked nature of the world, under the influence of globalization. However, this does not mean that we should sit back and wait for the situation to sort itself out. The interaction between man and technology can be instrumental in improving traffic flow.
Are you talking about the development of intelligent vehicles that use sensors, communications systems and other features to detect dangerous situations and critical bottlenecks well in advance?
That is one aspect. We are working on a new generation of automobiles that aim to facilitate networked mobility. In this case, it is the vehicles themselves that capture and pass on information so that their drivers can take steps to avoid congestion – at such an early stage that stop-and-go situations never arise in the first place. At the same time, though, drivers must also adapt their driving behavior.
Can you explain this in more concrete terms?
Studies have shown that there is such a thing as optimum driving behavior in traffic, but that it varies widely from situation to situation. There are situations in which it would be advisable to have greater distances between vehicles, in order to avoid rear-end collisions or to make it easier to change lanes. However, in areas where road works are being carried out, excessive gaps between cars could make capacity bottlenecks even worse. In future, there will be systems that assist drivers – especially in difficult situations such as these – while improving comfort, safety and traffic flow at the same time.
SCANNING THE FUTURE
One vision that is already becoming reality: networked vehicles exchange information and synchronize with each other for the optimum response to the traffic situation. In the not-too-distant future, it will be possible for a combination of sensor systems (radar components, laser scanners and image programs) to scan a car’s surroundings and provide an extensive electronic overall picture of the traffic situation. In association with the Universities of Oldenburg, Hanover and Braunschweig and with the support of the State of Lower Saxony, the Volkswagen Group is one of the driving forces behind a research initiative that is working to bring this vision to life. Adaptive Cruise Control (ACC) is already available for a number of Volkswagen models, slowing the car down according to its distance from the car in front or – a new development – accelerating again afterwards. In addition, the Front Scan environment observation system warns drivers if they get too close to vehicles in front and ”arms” the brakes in preparation for the driver to perform an emergency brake maneuver.