Mr. Popp, Mr. Kubitzki, so what exactly is “micro-sleep”?
Popp: We sleep specialists talk about so-called micro-sleep episodes, which we monitor in our sleep laboratory. The episodes can be very brief, but may also last for 10 to 15 seconds or even longer. And it's not always necessarily the case that your eyes are closed. The condition of sleepiness or fatigue is different for every person.
Kubitzki: The term micro-sleep suggests to some: "Oh well, the danger doesn't last long." However, at a certain level of fatigue you're simply no longer capable of completely concentrating on the task of driving. And if you should nod off for one or two seconds, the minutes before and after – actually, the whole trip, in fact – are also dangerous.
I must confess that I always have a can of energy drink in my glove box. Does it help?
Kubitzki: If you ask yourself during a journey what you can do when you get tired, I must honestly say that something has already gone wrong beforehand. This also applies if you rely on technical systems; these are at best emergency solutions.
Popp: The best cure for tiredness is in fact sleep – but please not behind the steering wheel, use a rest area instead! A “turbo sleep”, as the Swiss call it, lasting for 20 or 30 minutes
really helps. But it shouldn't go longer, otherwise your circulatory system will slow down, bringing you into deeper states of sleep. If you drink one or two coffees before your nap, this will even increase the caffeine's effect, as it takes 20 or 30 minutes for it to be absorbed in the bloodstream.
Turning up the radio, rolling down the window...
Popp: Neither works, as investigations in driving simulators and on the road have shown. On the contrary: If you subjectively feel more awake when there's loud music or cooler air –which objectively is not true – then you're underestimating the degree of your tiredness as well.