How Long After Drinking Is It Safe to Drive?

Having a drink isn’t dangerous (most times), but it can be deadly when you get behind the wheel after a glass or two or four.

Driving while drinking or within minutes of having consumed alcohol is not only devastating for you, but it has the potential to hurt anyone else who is around you as you drive. While the ideal solution to this problem is to order a cab after drinking, we know that may not be possible all the time. That’s why it’s important to know how long you need to wait before you can start that engine and press on that gas pedal.

In this article, we’ll consider how alcohol affects your driving skills and how long you need to actually wait before it’s safe to drive.

How does alcohol affect your ability to drive? 

Alcohol has the ability to interfere with the way the brain functions. The ingredients in alcohol affect the way in which the brain communicates with the rest of the body, thereby affecting what messages are received by your limbs and organs from the brain.

Recreational drinking can have short-term impacts such as –

• Slowing your reaction time.
• Impairing your ability to judge speed, distance and depth.
• Affecting your ability to perceive your surroundings and comprehend the situation.
• Reducing the effectiveness of your critical thinking and decision-making ability.
• Worsening your hand-eye coordination.
• Blurring your vision.

However, if a person drinks very consistently and in the long-term, alcohol can change the physicality of the brain, by damaging the ends of the brain’s neurons. This can prevent the brain from communicating important messages to the rest of the body, effectively distorting or sometimes destroying the communication pathway between the brain and the body.

Whether you drink recreationally or consistently, it’s important to remember that driving in such a mental and physical state, can be dangerous for you and other people around you.

Drink to drive: How long should you wait before you get behind the wheel? 

The time that you need to wait after consuming alcohol to drive, depends predominantly on how long it takes your body to completely metabolize the alcohol from your bloodstream. This can differ between individuals. For example, it can take about 2-3 hours for a pint of beer to metabolize fully in your body. But then again, it’s important to remember that not every alcohol is made the same. Depending on the ingredients used and the formulation process, different types of alcohol can take different times to metabolize in your body.

In order to arrive at an approximate timeline, scientists have suggested considering what alcohol percentage a standard drink would typically hold.

• 1 standard drink of beer would be 12 ounces and contain 5% alcohol.
• 1 standard drink of 80 proof liquor (such as whiskey, gin, rum, vodka, tequila) would be a 1.5-ounce shot and contain 40% alcohol.
• 1 standard drink of wine would be 5 ounces and contain 12% alcohol.
• 1 standard drink of fortified wine would be 3-4 ounces and contain 17% alcohol.

Depending on the alcohol and how many standard drinks you consume, it can take anywhere between 4 hours and 12 hours for the human body to completely metabolize the alcohol in your body.

So, does this mean that you can drive – at the most – after 12 hours of consuming alcohol?

Well, no. It’s not that simple.

Other factors matter too

Apart from beverage quantity and alcohol percentage, other factors impact how quickly alcohol is processed in your body. These factors include –

•   Age – Older people can take more time to process alcohol.
•   Weight – People at a higher weight will experience a higher level of intoxication.
•   Gender – Depending on their age and weight, sometimes men can take more time to process alcohol.
•   Time of meal & type of meal – The closer you’ve eaten to the time of drinking; the faster alcohol will be processed. Carb-heavy and protein-heavy foods absorb alcohol faster.
•   Genetics – Heredity will determine factors such as weight, body composition, alcohol metabolism rate etc.
•   Items/ingredients extraneous to alcohol – Adding certain juices, mixers or drugs to alcohol or taking medication when drinking can increase alcohol potency, while also increasing alcohol metabolism time.
•   Health conditions – Liver or kidney conditions can compromise the body’s ability to process alcohol properly. This can make your body feel intoxicated a lot longer.
•   Frequency of drinking – The Alcohol dehydrogenase enzymes produced in the body can effectively process light drinks taken by recreational drinkers quicker than those taken by heavy drinkers. Additionally, the livers of serious/heavy drinkers produce an enzyme called Cytocrome P450 2E1, which really zaps the body of energy, as it tries to metabolize large quantities of alcohol. This can make it very difficult for the individual to do daily tasks, like driving safely after drinking.

So, considering all of these factors, the 4-12 hours approximate metabolism time can be driven up or down significantly, on a person-to-person basis. Ideally, it’s best to give your body about 1 hour to metabolize each standard drink you’ve had. Multiply this time (1 hour) with the total number of standard drinks you’ve had and wait that long to drive. So, if you’ve had 5 standard drinks, wait for 5 hours before you drive. We also recommend that you eat a full carb/protein-heavy meal before getting in the car so that you feel more alert and energized.

But beyond this, there’s another factor that you need to be aware of before you get behind the wheel.

Legal considerations 

Although the alcohol can be metabolized by your body in a certain number of hours, traces of alcohol are still present in your body. This Blood Alcohol Content (BAC) can also impact whether you will legally be allowed to step foot into the driver’s seat after drinking.

In many countries around the world, law enforcement officials are allowed to check the BAC in your body, to determine your competency for driving after drinking. In the US, if you are found to have a BAC of 0.08% or above, it will be classified as “intoxication”, making you more likely to be given a DUI ticket. In other countries like India, a BAC of 0.04% is considered intoxication. In Australia, it is illegal to have any quantity of alcohol in your bloodstream. So, a rate lower than 0.04% is also punishable by law. If you do find yourself in a situation where you have been driving over the legal limit, you should discuss your options moving forward with your local Gold Coast Drink Driver Lawyer.

Depending on which BAC test you’ll be subjected to, law enforcement can find traces of alcohol in your body for a long time. For example –

• Breath analysis – BAC can be detected up to 24 hours after consuming alcohol.
• Urine analysis – BAC can be detected up to 12-48 hours after consuming alcohol.
• Hair analysis – BAC can be detected up to 90 days after consuming alcohol.

Usually, though, a breathalyzer (i.e., breath analysis) is the most common type of BAC testing done globally.

So, what should you do? 

Finally, what we recommend is this –

• Don’t drive. Designate a friend to be the driver, and ensure they don’t drink.
• If you can, sleep the alcohol off for the next 12 hours. Then drive.
• If you can’t be off the road for long, wait a minimum of 1 hour for every 1 standard drink you’ve had.
• Eat a carb and protein-heavy meal before/while drinking – and one before you start the drive.
• If driving while or after drinking has become a consistent and recurring problem, consult a qualified specialist to seek help with alcohol dependency.