Can I Get A DWI The Morning After Drinking?
As a DWI defense firm, we frequently hear from clients who are stunned to find themselves charged with driving while impaired (DWI) the morning after a night of drinking. They went to bed, woke up feeling fine, and assumed they were safe to drive—only to be pulled over and arrested for DWI. This scenario highlights a critical and often misunderstood aspect of the absorption, distribution, and elimination of alcohol (pharmacokinetics): you may feel sober, but your body may still be under the influence.
The Mellanby Effect: Why You May Feel Sober When You’re Not
One of the primary reasons for this disconnect between how you feel and your actual level of impairment is known as the Mellanby Effect. This phenomenon explains why a person’s subjective experience of impairment can differ significantly depending on whether their blood alcohol concentration (BAC) is rising or falling.
When you drink, your body absorbs alcohol and your BAC rises. During this time, you’ll feel the effects of the alcohol. However, when your BAC starts to decline, such as when you’ve stopped drinking and gone to bed, you may not feel impaired. Unfortunately, this subjective feeling can be deceptive. Even though you feel better, your BAC might still be above .08.
A Personal Example of the Mellanby Effect in Action
We personally can attest to the Mellanby Effect. Several years ago, one of our lawyers participated in a controlled drinking experiment as part of a science course. After consuming a prescribed amount of alcohol over a specified duration, he provided his first alcohol sample. At that point, he felt impaired and said he would not have driven. His measured BAC was 0.09, just over the legal limit.
As the experiment continued, he slowly consumed alcohol over the next few hours but wasn’t tested. Eventually, he switched to water. When it came time to provide a final alcohol sample, he subjectively felt much less impaired than before, and even believed his BAC would be under the legal limit of 0.08%. To his surprise, the test revealed his BAC was actually 0.11%—well above the legal limit!
This experiment is a perfect example of the Mellanby Effect in action. Despite feeling “sober” as his BAC decreased, his level of impairment and risk of arrest were still significant.
The Science Behind the Mellanby Effect
The Mellanby Effect was first described in 1919 by Sir Edward Mellanby, who discovered that individuals feel more impaired as their BAC rises than they do at the same BAC level when it is falling. This means that someone with a BAC of 0.08%, while their levels are increasing, will feel much more intoxicated than someone with the exact same BAC when it is decreasing. This difference is largely due to your brain adapting to the effects of alcohol and your body’s metabolic response.
In essence, your brain's perception of sobriety lags behind your actual BAC levels. After a night of drinking, you might wake up with a BAC that is still over the legal limit, even if you feel clear-headed and alert. Relying on your subjective feelings can get you arrested for DWI the night after drinking.
The Morning After: The Risks of Driving While Feeling “Sober”
Driving the morning after drinking can still be legally and physically risky. Here are some key points to consider:
- Your BAC May Still Be Elevated:
After a night of drinking, alcohol is metabolized slowly—about 0.015% per hour on average (this rate may slow as your BAC gets below 0.08). If you went to bed with a BAC of 0.15%, it could take 10 hours or more for you to reach a BAC of 0.00%. So even if you stop drinking at midnight, your BAC could still be over the legal limit when you wake up at 7 a.m. - Lingering Impairment Despite Low BAC:
Even if your BAC has fallen below the legal threshold of 0.08%, you may still be experiencing residual effects such as slower reaction times, impaired coordination, and poor decision-making skills. This is especially true for those who drank heavily the night before. - Subjective Sobriety is Not Objective Sobriety:
The Mellanby Effect highlights a critical gap between feeling sober and being sober. This means you can feel capable of driving but still be too impaired to operate a vehicle safely. - Legal Consequences Remain:
If you are stopped by law enforcement the morning after drinking, you could still be arrested for a DUI or DWI if your BAC is above the legal limit. Even if your BAC is below 0.08%, erratic driving or visible signs of impairment can lead to an arrest. The officer’s observations of your behavior and performance on field sobriety tests can play a significant role in whether you are charged. - Sleeping in your Vehicle may be Treated as Driving: Under Minnesota law, you can be arrested even if you're not driving. Minnesota makes it a crime not only to drive while drunk but also to "operate” or be in "physical control." Even if you think you're being responsible and sleeping in your car, if you have the keys, you may be in "physical control” while impaired. This is treated the same as drunk driving in Minnesota!
Practical Tips to Avoid the Morning-After DWI
Understanding the Mellanby Effect and the slow rate at which your body metabolizes alcohol can help you make safer decisions. Here are some practical tips to avoid finding yourself in this situation:
- Plan Ahead:.
If you plan to drink, arrange for alternative transportation the next morning. Consider staying overnight near your destination or using a ride-sharing service, even the next day. - Be Aware of Your Consumption:
Keep track of how much you’re drinking. Remember, “sleeping it off” does not guarantee sobriety. The more you consume, the longer it will take to be safe behind the wheel. - Use a Personal Breathalyzer with Caution:
Personal breathalyzers can offer a rough estimate of your BAC, but they are not always accurate and should not be relied upon as the sole indicator of your ability to drive. - Listen to Your Body, But Trust the Science:
If you doubt your sobriety, err on the side of caution. Your subjective feelings can be misleading due to the Mellanby Effect.
Conclusion: Awareness is Key
Getting arrested for DWI the morning after drinking is a real and all-too-common scenario that catches many drivers by surprise. Understanding the Mellanby Effect and the slow rate of alcohol metabolism can help you make safer choices. While you may feel fine, the law and science may not agree. Be mindful of the risks and plan accordingly to avoid the legal and personal consequences of impaired driving -- even when you're just sleeping in the backseat!
If you have any questions or need legal assistance, don’t hesitate to reach out. At Ramsay Law Firm, we’re here to provide guidance, defend your rights, and help you understand the complexities of DWI law.