It is well known that driving under the influence of alcohol is dangerous, but until recently, there hasn't been much attention paid to driving while under the influence of a hangover.

More than traffic laws, road, or traffic conditions, an individual's state of mind is the primary factor in determining whether or not that individual will drive safely. Being late and the irritation that brings may tempt you to drive faster and take more chances such as trying to make it through an intersection before the light turns red. Driving under the influence of a bad cold or flu affects your vision and your reaction time. Driving when you are in a good mood and in no particular hurry may lessen the temptation to speed or to run that light. Driving with a hangover with its associated headaches, sensitivity to light, gastrointestinal problems, and irritability are not going to put you into an alert or stress-free state of mind.

Hangovers can start while there is still some measurable alcohol in the system and generally reach their peak at about the time the Blood Alcohol Content (BAC) is reduced to zero. They can last anywhere from 8 to 24 hours after the BAC reaches zero. Factors leading to a hangover include:
•Dehydration - Alcohol has a dehydrating effect, reducing the amount of fluids in the body and the brain. The dehydration also leads to a deficiency of important minerals such as magnesium and potassium. Symptoms of dehydration include lightheadedness, lethargy, headache, and thirst.
•Glucose reduction - Working to metabolize the alcohol out of the system impairs the liver's ability to supply glucose to the tissues and organs (primarily the brain). Since glucose provides the organs with the energy necessary to do their jobs, the reduction of glucose in the system leads to fatigue, weakness, mood disturbances, decreased attention, and concentration.
•Sleep deprivation – Sufferers generally have decreased sleep, decreased REM sleep and increased slow-wave sleep.
•Gastrointestinal – Alcohol has an irritating effect on the stomach and intestinal linings and slows the emptying of the stomach.

While it should be obvious that all of these symptoms will affect a driver's ability, a recent study by Brunel University in England on the effects of driving while hungover revealed some interesting data. The study's subjects were observed driving a five-mile course in driving simulators while sober and while experiencing the effects of a hangover. When comparing the two tests, it was found that:
•Hungover drivers drove an average of 10 mph faster.
•The average speed for sober drivers was 32.6 mph but rose to 41.7 mph for hungover drivers.
•Hungover drivers drove above the speed limit 26% of the time compared to only 6.3% of the time while sober.
•Hungover drivers left their lane four times as often as sober drivers.
•Hungover drivers committed double the number of traffic violations, such as running red lights.
•Traffic violations rose from an average of 3.9 for sober drivers to 8.5 for hungover drivers.

With symptoms such as light sensitivity, headache and lethargy, one surprising result of the study was how fast the hungover drivers drove. One of the study's authors said, "It's as if they are in a daze, thinking 'I have to get to work. I'll get there as fast as I can and take an Alka Seltzer to feel better when I get there."

Speeding, leaving the lane, and committing more traffic offenses, along with the reduced reaction time caused by a hangover, can lead to a deadly situation. To reduce the effects of a hangover, experts provide the following suggestions:
•Pace yourself. Drink more slowly and include water or other non-alcoholic drinks to keep hydrated.
•Eat to slow the absorption of alcohol into the bloodstream.
•Eat fruits and drink fruit juices to reduce the effects of hangovers.
•Eat bland foods such as crackers to increase glucose levels and reduce nausea.

If you are already feeling the effects of a hangover:
•Drink sports drinks to increase electrolytes and to keep hydrated.
•Take antacids to reduce the gastrointestinal pain and nausea.
•Take aspirin or other anti-inflammatory drugs (Do not take acetaminophen, which is toxic to the liver when it interacts with alcohol).
•Do not drink more alcohol. It only makes the situation worse.
•Above all, don’t drive when you are feeling the effects of a hangover.