Mercedes-Benz accident researchers warn against falling asleep momentarily whilst driving. Drivers who do not take regular breaks when driving long distances run a high risk of becoming drowsy – a state which they often fail to recognise early enough according to the experts. This is why Mercedes-Benz has developed the innovative ATTENTION ASSIST system, which can detect when drivers start to become drowsy and prompt them to take a break before it's too late. The system will be fitted as standard in the new E-Class and the model year 2009 S-Class.

Scientific studies conclude that around 25 percent of all serious motorway accidents are down to driver drowsiness, meaning that drowsiness causes more road accidents than drunk-driving.

The risk of falling asleep momentarily is at its greatest on long-distance journeys in the dark or in unchanging conditions because this is when drivers are most likely to suffer a lapse in attention. The sheer monotony further heightens the risk of falling asleep at the wheel. Studies show that, after just four hours of non-stop driving, drivers' reaction times can be up to 50 percent slower. So the risk of an accident doubles during this time. And the risk increases more than eight-fold after just six hours of non-stop driving!

The newly developed ATTENTION ASSIST system sees Mercedes-Benz continuing to adopt a practically-oriented stance towards accident avoidance. A stance which has already lead to a proven improvement in road safety thanks to developments such as the Electronic Stability Program (ESP®) and Brake Assist.

ATTENTION ASSIST observes the driver's behaviour and, at the start of every trip, produces an individual driver profile that is then continuously compared with current sensor data. This permanent form of monitoring is important for detecting the floating transition from awakeness to drowsiness and for warning the driver in plenty of time. The system is active at speeds of between 80 and 180 km/h.

Steering behaviour as the key indicator of drowsiness

As well as the speed, lateral acceleration and longitudinal acceleration, the Mercedes system also detects steering wheel movements, use of the turn indicators or pedals and certain control inputs, not to mention external influences such as side winds or road unevenness, for example. Observation of steering behaviour has proven to be extremely meaningful as drowsy drivers find it difficult to steer a precise course in their lane. They make minor steering errors that are often corrected quickly and abruptly. Intensive tests carried out by the Mercedes engineers, involving more than 550 drivers, show that this effect occurs at a very early stage when drowsiness kicks in – often before the dangerous situation in which the driver falls asleep momentarily.

ATTENTION ASSIST: how the Mercedes system detects drowsiness

At the heart of this Mercedes system is a highly sensitive sensor which allows extremely precise monitoring of the steering wheel movements and the steering speed.

Based on these data, ATTENTION ASSIST calculates an individual behavioural pattern during the first few minutes of every trip. This pattern is then continuously compared with the current steering behaviour and the current driving situation, courtesy of the vehicle's electronic control unit. This process allows the system to detect typical indicators of drowsiness and warn the driver by emitting an audible signal and flashing up an unequivocal instruction on the display in the instrument cluster: "ATTENTION ASSIST. Break!"


Blind Spot Assist: Radar sensors monitor the areas directly alongside and behind the car

Blind Spot Assist, developed by Mercedes-Benz, uses radar technology to monitor the areas directly alongside and behind the car. It warns the driver when changing lanes would be too dangerous.

Every year, around 9,500 serious road accidents in Germany are caused by motorists who fail to take heed of the traffic behind when changing lanes or cut across in front of another vehicle too soon after overtaking.

The Mercedes assistance system can help drivers to change lanes safely: short-range radar sensors housed on both sides of the rear bumper monitor the areas directly alongside and behind the car. This process enables them to see if there is another vehicle in the next lane – in the so-called blind spot. In such situations, the system informs the driver by illuminating a red warning signal in the glass of the exterior mirror. If the driver fails to see this warning and indicates to change lanes, a warning signal sounds as well.


DISTRONIC PLUS/Brake Assist PLUS: Radar-based assistance systems can prevent 20 percent of all head-to-tail crashes

DISTRONIC PLUS and Brake Assist PLUS – Mercedes assistance systems based on sophisticated radar technology – are highly effective at helping to prevent accidents. This is one of the findings of an analysis carried out by Mercedes-Benz based on representative accident-research data. This technology can prevent a fifth of all head-to-tail crashes in Germany alone. On motorways, the accident rate can be reduced by as much as around 36 percent. Mercedes-Benz has further enhanced the radar technology for the new E-Class and the model year 2009 S-Class.

Every year in Germany there are over 50,000 serious head-to-tail crashes, in which some 5700 people are either killed or seriously injured. One in six traffic accidents in which people are injured is down to a head-to-tail crash. The situation is even more serious in the US, where this type of collision accounts for around 30 percent of all serious road accidents.

In developing the DISTRONIC PLUS and Brake Assist PLUSradar-based assistance systems, which have been available for the S-Class since 2005 and the CL-Class since 2006, Mercedes-Benz has made an important contribution towards preventing head-to-tail crashes. This is one of the findings of the latest accident research carried out at Mercedes, based on the reconstruction of over 800 head-to-tail crashes. The representative study focussed on one question in particular: how many accidents of this type could be prevented if all passenger cars were equipped with this Mercedes technology?

The results confirm the considerable safety-enhancing effect of the assistance systems: DISTRONIC PLUS and Brake Assist PLUS prevent over 20 percent of head-to-tail crashes on average. In another quarter of these collisions, the systems can help to greatly reduce accident severity. This combination of state-of-the-art radar and brake technology offers the greatest safety potential on motorways, where around 36 percent of all head-to-tail crashes can be prevented.

Warns and assists the driver as well as providing emergency braking

DISTRONIC PLUS proximity control operates at speeds of between 0 and 200 km/h: it keeps the car a set distance behind the vehicle in front, applies the brakes as required and can even bring the car to a complete halt, depending on the traffic situation. If the gap to the vehicle in front narrows too quickly, the system gives the driver an audible warning and, as soon as this first warning signal sounds, automatically calculates the brake pressure required to prevent a collision in this situation.

This technology helps the driver to gauge the level of risk and makes the calculated brake boosting force available instantly, even if the driver does not press the brake pedal forcefully enough. Brake Assist PLUS allows controlled, targeted braking and, if necessary, increases the braking force right up to the point at which an emergency stop is performed, depending on the road speed and the distance to the vehicle in front.

New radar sensor with extended range and medium-range detection capability

When a potential accident situation is recognised, assistance is provided courtesy of two short-range radar sensors behind the front bumper and a long-range radar in the radiator grille. Mercedes-Benz has further enhanced the performance capability of these sensors. In the new E-Class and model year 2009 S-Class, Mercedes-Benz uses a newly developed sensor with a range of 200 metres – instead of 150 metres, as previously – for the long-range radar. In addition, the sensor now also has medium-range detection capability, allowing monitoring of the area up to around 60 metres ahead of the car with a 60-degree beam width. This new technology enables even more precise monitoring of the traffic situation in front of the car and even better detection of dynamic events such as a car in front swerving suddenly. The two wide-beam short-range radar sensors (80‑degree beam width) with a range of around 30 metres are still employed.

40 percent of all S-Class saloons are equipped with radar

Mercedes-Benz offers DISTRONIC PLUS in combination with Brake Assist PLUS as an optional extra. Around 40 percent of customers buying new S-Class models in Germany specify this safety technology; in the case of the CL-Class, over 70 percent of customers order DISTRONIC PLUS and Brake Assist PLUS. Since 2005, Mercedes-Benz has supplied customers with over 50,000 cars featuring these innovative systems.






















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