According to various scientific studies, between 10 and 20 per cent of serious traffic accidents can be attributed to drowsiness and fatigue. In the U.S. alone, over 100,000 accidents are caused by driver fatigue every year, in which 1,500 people are killed and a further 71,000 injured. So Mercedes-Benz is developing a warning system for sleepy drivers. An interdisciplinary team of engineers, computer scientists and psychologists at Mercedes-Benz is developing a system to save many lives and which should be ready in a few years.
Before looking at the Mercedes project, I want to tell you why I was reluctant to write about it before. There are literally dozens of car-related websites and blogs talking about this initiative, and the ones who dare to mention a source say it's a press release from the DaimlerChrysler group.
But there is no press release about this project, neither on the DaimlerChrysler website or on the Mercedes-Benz one. Moreover, I've searched specifically for press releases via specialized search engines and I haven't found anything. Does this mean the information is fake or that someone had a privileged access to some valid information? As I think that it would be difficult to mislead so many specialized sites, I've concluded that the information was valid even if I didn't have access to the source.
So let's start with why a tired driver is dangerous for himself and others. Simply, he has reactions similar to a drunken driver.
The phenomenon that threatens to occur in this type of situation is referred to by experts as "microsleep": a spontaneous reaction of the human organism to over-fatigue. The eyes sting, the lids blink more frequently but more slowly too, the pupils become smaller, the driver yawns and shivers -- all telltale warning signs of this phenomenon. Should the eyes remain closed for just one second longer than usual the consequences can be fatal, as in this second the car covers a whole 28 metres when travelling at a speed of 100 km/h - effectively driverless and therefore out of control.
So what are doing the Mercedes-Benz experts to fight this state? They've used a variety of methods for detecting driver fatigue as soon as it sets in.
One of these techniques is the eye-blink observation method: an infrared camera directed at the driver's head permanently monitors the eye-blink frequency, enabling microsleep to be detected the instant the eyes stay closed for a certain period of time. A warning signal sounds in the car's cockpit in response.
Below is a picture of a driver equipped with various sensors placed by Mercedes-Benz engineers. (Credit: DaimlerChrysler, via The Auto Channel) Here is a link to a larger version (4,992 x 3,328 pixels, 3.07 MB).
The team also used other methods, all being more or less intrusive in my opinion.
In order to obtain objective indicators of fatigue, other physiological readings such as the electroencephalogram (EEG) are used. Yet another method is based on the analysis of dynamic driving data, such as steering or braking characteristics. One of the systems triggers an alarm if the driver does not move the steering wheel for a prolonged period of time.
But of course, you also can try to entertain a driver before he falls asleep. So why not watching TV when driving these long distances at night? (Credit: DaimlerChrysler, via TopSpeed) Here is a link to a larger version (4,992 x 3,328 pixels, 2.36 MB).
Anyway, are automotive companies ready to launch such a system? And is it efficient?
Initial results obtained by the engineers in Sindelfingen indicate that the observation of individual criteria alone does not allow reliable detection of tiredness. Fatigue is a highly complex phenomenon that can manifest itself in all manner of ways. In view of this, Mercedes-Benz will make use of a whole host of factors for fatigue detection, including the individual driving style, the duration of the journey, the time of day and the current traffic situation. By continually comparing this data with stored empirical values, the system will be able to compile an individual driver profile and use probability calculus to determine whether the driver is exhibiting the first signs of fatigue.
Not only you would have to use special equipment, but the engineers are not sure if their system will work. So here is a good advice for all of you. If you have long trips to do in a car or a truck, be sure to take some rest and stop some place from time to time -- after two hours of driving, your attention decreases...
Sources: DaimlerChrysler information, via various websites
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