Alcohol & Driving

The Effects of Alcohol on Behavior and Motor Skills

The National Safety Council has developed the guide below as a very general source of information about alcohol’s effects on behavior and on driving ability.

It is reproduced here for information purposes only. Your Drug and Poison Information Center wants you to know that about 50% of all traffic fatalities are alcohol related and that there is no such thing as a “safe” level of alcohol when it comes to driving, flying an airplane or operating dangerous machines.

The legal drunk level is just that, a level that poses the risk of a driver being arrested and charged with drunk driving.  

Lower levels can and do significantly impair driving abilities, reaction time, and judgement and such levels have been associated with many “accidents” and deaths.

Even at a level of 0.05, the chances of an automobile accident occurring are twice as great as they would be if the driver hadn’t been drinking.

Driving when one has a “hangover” is also associated with a higher than normal risk of accidents.

No. of beers or one oz. servings of liquor Blood alcohol concentration Effects on feeling and behavior Effects on driving ability
1 0.02 Absence of observable effects. Mild alteration of feelings, slight intensification of moods. Mild changes. Most drivers seem a bit moody. Bad driving habits slightly pronounced.
2 to 3 0.05 Feeling of relaxation. Mild sedation. Exaggerated emotions and behavior. Slight impairment of motor skills. Drivers take too long to decide and act. Motor skills (such as braking) impaired.
5 to 6 0.1 Difficulty performing gross motor skills. Uncoordinated behavior. Impairment of mental abilities, judgement and memory. Judgement seriously affected. Physical and mental coordination impaired. Physical difficulty in driving a vehicle.
7 to 8 0.15 Major impairment of physical and mental functions. Irresponsible behavior. Euphoria. Some difficulty standing, walking and talking. Distortion of perception and judgement. Driving erratic. Driver in a daze.
15 to 20 0.4 At this point, most people have passed out. Driver probably has passed out.


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