Vehicle manufacturer Mercedes-Benz is to introduce the driver support system Attention Assist into its production line-up in 2009.

Attention Assist is able to recognise driver fatigue at an early stage, signalling a warning that the driver needs to take a break.

According to Mercedes-Benz, scientific studies indicate that around 25% of all serious highway accidents are caused by overtired drivers – which makes it an even bigger cause of accidents than driving under the influence of alcohol.

The monotony of completing long journeys at night, or under unchanging conditions at a constant cruising speed, creates the risk of the so-called “one-second nap”, which leads to accidents.

Studies have shown that the reaction times of drivers can be 50% longer after only four hours of nonstop driving. This means the risk of an accident is doubled after this length of time.

After six hours of driving it is no less than eight times as high.

Mercedes-Benz says Attention Assist counters the one-second nap by monitoring the driver – generating an individual profile – which is then constantly compared to a flow of data, collected by various sensors.

This continuous monitoring is important as it enables the system to recognise the driver’s transition from being alert to becoming drowsy, warning him or her in good time.

In addition to vehicle speed and acceleration, the Mercedes system registers steering wheel movements, indicator and pedal operation, plus a number of specific control operations and external influences, such as uneven road surfaces.

Steering characteristics are the most important indicator of fatigue, as an overtired driver has difficulty in keeping the vehicle precisely on track.

He or she often makes minor steering errors which are quickly corrected in a characteristic manner.

Intensive tests by Mercedes engineers involving more than 550 male and female drivers have shown that this effect already starts at the early onset of fatigue – usually before the highly dangerous “one-second nap”.

This is why Attention Assist uses this data to compile an individual driver behaviour pattern during the first few minutes of each journey. The onboard electronic control unit then compares this data with later steering behaviour.

This enables the system to recognise the typical signs of fatigue, warning the driver accordingly. This is done by an acoustic signal and a display in the instrument cluster with the clear-cut advice: “Attention Assist. Break!”

Mercedes-Benz South Africa says Attention Assist will be a standard feature on the new E-Class being launched locally mid-2009.