Most of us have been in this situation. Youre driving along and your thoughts wander off momentarily, when all the sudden you realize that your car is slowly veering into the adjacent lane. You quickly get a jolt of adrenaline as you straighten up your wheel. And this pattern will repeat until you get home, get coffee, or get into a car accident. Even when youre not consciously tired this pattern will occur to a lesser extend (weaving on the road). It would be easy enough, I think, to detect this wobble pattern and distinguish it from normal turns on the road (the latter generally being much less abrupt). When the car detects that the amplitude of this wobble is larger than some threshold, is should turn on a warning light and/or a buzzer. Realizing that youre drowsy will probably be enough for most drivers to do something about it. State law might eventually mandate installing tamper-proof light indicators, so that other drivers could be warned that theres a drowsy driver on the road. Drivers would probably resist such a law, but it would be a huge improvement to road safety if it would be done.-- imho, May 31 2009 Does more than detect... Slap-Hat [theleopard, May 31 2009] Drowsiness Pattern Detection http://www.autoweek...1224/FREE/812249991 [loonquawl, Jun 02 2009] we've discussed drowsy drivers before (you might care to search the vehicle section) not sure how you deal with absent-minded or distracted drivers though.-- po, May 31 2009 I smell the scent of the noxious fumes of *shameless elf promotion*, in the words of Hugo (that's Hugo Chavez, not Victor Hugo) "It still smells of sulphur today".-- 4whom, May 31 2009 You make a good point. This idea entirely relies on reliably distinguishing "pot-hole swerving" from "drowsy weaving". I have a hunch it can be done. For example, drowsy driving will tend to have slow meanderings followed by a rapid correction. Whereas "pot-hole swerving" tends to be more sinusoidal. But obviously this phenomenon would need to be systematically studied.-- imho, May 31 2009 Your hunch is right. Daimler inlcuded it in the new E-class Mercedes. They had a research program linking brainwaves (objective measure of drowsiness) to steering behaviour and identified markers. The car now monitors your driving and alerts you if your pattern gets weird. [link]-- loonquawl, Jun 02 2009 random, halfbakery