Sudden, torrential downpours are one of the most hazardous weather phenomena facing drivers – and according to the latest studies, such events are set to become increasingly common in the future, particularly in summer. In heavy rain, aquaplaning can pose a real hazard. But help is at hand, thanks to innovative assistance systems that prevent accidents by detecting critical situations at any early stage.
A warm summer breeze drifts languidly through the half-open windows. The sun is sinking slowly toward the western horizon and Bryan Adams’s “Summer of 69” is playing on the radio. It’s a classic image of driving at its delightful best. But such moments can be all too fleeting. All of a sudden, heavy cloud cover rolls across the sun, banishing the blue skies and plunging the idyllic panorama into an almost eerie darkness.
Such apocalyptic scenes, almost like something out of a Hollywood disaster movie, are a frequent prelude to a weather phenomenon which, according to a recent analysis of radar data by the German Meteorological Society, could become all too common in Europe in the future: torrential rain. When huge amounts of water descend from the sky in a very short space of time, the consequences can be dramatic. When the drains are overwhelmed and the soil saturated, the roads and surrounding countryside can quickly disappear under floodwater. Rainfall of this intensity is becoming more and more frequent, particularly in the spring and summer months. Typically, such heavy rainfall events tend to develop suddenly and are very localized, rarely affecting a whole region – which is why weather apps, for example, find them so hard to predict. You drive into a tunnel in brilliant sunshine at one end, only to emerge into a downpour at the other. That “Summer of 69” vibe on the commute home can all too quickly morph into “Riders on the Storm” with a sudden real risk of aquaplaning. This risk exists no matter how good the tires on your car may be, because in flash flooding the tread is sometimes no longer able to displace the water to the sides fast enough. A wedge of water builds up in front of the tire and pushes its way underneath, so that the car ends up floating and losing contact with the road. When this happens, the driver can no longer control the vehicle and even assistance systems like Electronic Stability Control (ESC) or the Antilock Braking System (ABS) are powerless to help. Some 39 percent of all road accidents are attributed to extreme weather conditions of this type.
However, state-of-the-art safety technologies will soon be at hand to help drivers and vehicles to reduce the risk of aquaplaning. Continental is at the forefront of this development work: “Even with the best tires, the sudden onset of aquaplaning is always a frightening moment. We are currently developing a high-performance technology based on sensor information and software that detects a potential risk of aquaplaning and warns the driver in good time,” says Frank Jourdan, member of the Continental Executive Board and head of the Chassis & Safety division. To detect unusual levels of water displacement, Continental uses images from wide-angle surround-view cameras. These cameras are installed in the door mirrors, the radiator grille and at the rear of Continental’s research vehicles. “When there is a lot of water on the road, the images show a specific splash and spray pattern from the tires. Our algorithms utilize this pattern to identify any risk of aquaplaning,” explains Bernd Hartmann who heads up the Driver Assistance & Tire Interactions project group in the Advanced Technology department at Continental’s Chassis & Safety division. This means drivers can be warned in good time so they can better adjust their speed before things get critical. Potentially this technology, which is currently at the predevelopment stage, could be ready to go into production in the next generation of vehicles.
In the future, thanks to digitalization and the spread of connectivity, it will also be possible to provide advance warnings for following traffic too. A V2X-equipped vehicle that encounters aquaplaning can inform other vehicles of the upcoming hazard. This is where Continental’s eHorizon system comes in, a big data cloud solution that gives vehicles a preview of the road ahead and feeds information to the driver assistance systems. If there is a critical depth of water on the road round the next corner, drivers can be made aware of it well in advance and reduce their speed accordingly, minimizing the risk of an accident.
Further information can be supplied by the tire itself, more specifically by the tire-mounted Continental eTis (electronic-Tire Information System) sensors. As well as calculating an appropriate speed based on the detected tread depth and information about road conditions, the system can also analyze data from the acceleration sensors to detect aquaplaning at an early stage. If the tire tread is no longer able to displace the water fast enough, the system immediately recognizes this specific pattern and alerts the driver to the risk of aquaplaning.
The major automakers too consider aquaplaning a growing problem. Porsche, for example, has equipped the new generation of its 911 model with a “wet mode”. This technology uses acoustic sensors in the front wheel arches to measure spray. The sensors are even smart enough to be able to distinguish water from sand or dirt, based on the differences in frequency pattern. As soon as the sensors detect a critical volume of water on the road, the driver receives a recommendation to activate “wet mode”. Various vehicle systems then adapt their setup accordingly. This includes switching to a softer throttle response, a different transmission setup and more sensitive settings for the ABS and traction control. At the same time the front cooling flaps are opened all the way and the rear spoiler is deployed, modifying the vehicle’s aerodynamic characteristics to create maximum downforce and enhanced stability. This system can also activate car-to-car communication, allowing the acquired data to be passed on to other vehicles. The effect is to create a kind of inter-vehicle solidarity network, in which vehicles are able to share critical information in the interests of greater safety.
The auto industry is developing technologies for a future in which heavy rainfall events in Europe look set to become more frequent. But of course, this work is not just focused on the European markets. After all, “Vision Zero”, the vision of crash-free driving, is a global approach that transcends national boundaries. India, for example, where Continental now employs some 8,000 people and is currently building two more plants, is a country where vehicle production has seen steady growth in recent years, but which is at the same time also prone to violent rainstorms, particularly between June and September. This results in a high risk of aquaplaning. “India is on its way to becoming the world’s third-largest vehicle market,” says Günter Butschek, CEO and Managing Director of Indian auto manufacturer Tata Motors. But if the motorization of India’s 1.3 billion population continues at its present rate, something must be done to help drivers cope with the rainy season. The systems now being developed by Continental and other technology companies offer an answer – one that will mark a further step on the road to a crash-free future.
|How best to deal with aquaplaning|
First the basics: Check your tires regularly to ensure that they still have enough tread. With summer tires a minimum of 3 millimeters is recommended while winter tires should have at least 4 millimeters of tread. And make sure your tire pressures are right. You will find the correct pressures on a label on your vehicle
1.) Keep both hands on the steering wheel