We all know the risks of drinking and driving, and yet even with massive advertising, stringent enforcement and severe penalties; driving while intoxicated remains a substantial and too often tragic problem in our society. But even those of us who do endeavor to stay under the legal blood alcohol limit may be placing ourselves and others in danger if we drink even a small amount of alcohol and drive, while very sleepy.
Testing the pros…
Australian university researchers wanted to investigate the influence of sleepiness and low doses of alcohol on driver performance, and to do this they enlisted the help of a number of professional drivers. Over successive days, these drivers where given performance tests on a driving simulator, either sober and wakeful (awake for 12-15 hours), having consumed alcohol and wakeful (blood alcohol levels of 0.03 and 0.05) and then the tests were performed again (0.0, 0.03,) when the drivers were sleepy, after having been awake for 18-21 hours.
So does being sleepy matter?
The researchers found that sleepy drivers who had consumed only a small amount of alcohol (blood alcohol levels of 0.03) did worse on reactions and performance testing than did the wakeful drivers who had consumed a greater amount of alcohol (0.05 blood alcohol) and researchers extrapolate that with more alcohol consumption, the impact of sleepiness would grow more significant.
What this means?
Most of us don’t drink and drive for two major reasons. Firstly, we have a social conscious and are aware of the destruction wrought by intoxicated drivers, and we have no wish to cause or suffer the pains of a drunken driving accident. Secondly, we also fear penalties if caught driving drunk; and a combination of these two factors is enough to keep the majority of people off the roads after drinking too excess.
Our false assumptions
We also assume that blood alcohol levels are determined with road safety in mind, and that if we remain under the legal alcohol limit, we therefore retain the ability to drive safely. Unfortunately, this study tells us that our assumptions may be false. If you drink while very sleepy, and stay just under the legal limit–theoretically safe to drive–your reaction times more likely equal someone who is well above the legal limit, and both of you represent a danger to self and others. Take it easy, be safe, and avoid the heartbreak of a DUI tragedy.