Alcohol is a major contributor to motorcycle crashes, especially fatal crashes. Statistical data shows 45 to 50% of all riders killed in motorcycle accidents had been drinking. One third of these riders had a blood-alcohol concentration (BAC) above the legal limit. The remaining two thirds had only a drink or two, while not legally intoxicated, but enough to impair their judgment and motor skills needed to ride safely.
Blood Alcohol Concentration
Blood Alcohol Concentration (BAC) refers to the amount of alcohol in the blood. The more alcohol in your body, the higher your BAC. Most people with a BAC between .08% and .10% can no longer function normally and in most states are legally intoxicated. It is important to know that these people were impaired well before reaching .08%. It starts with the first drink, because alcohol works fast into the bloodstream.
Note: In Minnesota it is against the law to operate a motor vehicle while intoxicated with a BAC level of .08% or above. More information about Minnesota state laws regarding operating a motor vehicle while intoxicated can be found at alcohol and the law
BAC is affected by three factors; the amount of alcohol consumed, the time frame within it is consumed, and the body weight of the drinker. The rule of thumb in defining an alcoholic beverage drink is that it contains one ounce of pure ethyl alcohol. A 12-ounce can of beer, a 5-ounce glass of wine or a shot of liquor all contain about the same amount of alcohol. Another rule of thumb is that it takes one hour to eliminate the effects of one drink. The faster a person drinks the more alcohol accumulates in the bloodstream. So if a person had two drinks within an hour, there would still be the alcohol from one drink remaining in the bloodstream. The physical size of the person is a factor in determining BAC. Considering that a large and small person drank the same amount of alcohol over the same amount of time, the smaller person would have a higher BAC level. The reason is that the smaller person has less blood volume to base the percentage.
To give you an idea about what your BAC level might be based on your weight, percentage of alcohol in your beverage, and how many alcohol drinks you consume in a given time period, check out the interactive BAC Calculator.
It might be easier to get an overall perspective when you look at reference tables. Below is a reference table for men and women to estimate your level of alcohol impairment when comparing weight and number of drinks consumed. Information on these tables, like the interactive BAC Calculator mentioned above are illustrative only and indicate average or typical BAC levels. This information should never take the place of your own decision about whether to ride a motorcycle after drinking alcohol. Note that the only safe limit on both of these charts is indicated when no alcohol is consumed.