The problems caused by fatigued drivers are well known. When it comes to trucks, the HOS regulations are supposed to prevent drivers from becoming fatigued to the point of being dangerous. This is fine in theory, but the practical reality is it doesn’t always work.
Even a driver who is well within the legal hours of service could be fatigued. For years, I’ve been watching for something that might be useful in this regard.
A story at: http://www.dailymail.co.uk/sciencetech/article-1218545/SmartCap-invented-warns-drivers-nod-off.html talk of a new invention called the "Smart Cap" This is pretty cool. There are sensors in the hat that send a driver’s brainwaves to a computer, where an algorithm determines if a driver is becoming fatigued. Preliminary testing in Australia has yielded some positive results.
Another technology (also from Australia) is the Optalert (http://www.optalert.com/) This works using a pair of glasses with sensors that monitor a driver’s eye and eyelid movements. When it detects a potential fatigue situation, it warns the driver.
All in all, pretty cool stuff. It’ll be interesting to see how it all works in the long term.