Dangers of Drinking and Driving: How Does Alcohol Affect Your Driving?

Alcohol and driving is a dangerous and frequently deadly combination. About one-third of fatal car crashes in the United States in 2019 involved drunk drivers1. Every day, 29 people in the U.S. die in an alcohol-related car crash, equaling one preventable death every 50 minutes2.

In this post, we’ll answer the question: How can drinking alcohol affect your ability to drive? We’ll also examine the consequences of drinking and driving, and what you can do to get problem drinking under control.

How Does Alcohol Affect Your Driving?

two men driving in a car
Photo by Orkun Azap on Unsplash

Alcohol impairs vision, reaction time, coordination, and judgment, all of which are essential to safe driving. It’s also linked to aggression, meaning it can fuel road rage incidents.


Visual functions begin to decline with a blood alcohol concentration (BAC) of just .02%, the equivalent of only one to two drinks3. It becomes harder for your eyes to rapidly track moving objects, like cars or pedestrians.

After about three drinks, when your BAC reaches .05%, you may also lose control of small muscles in your eyes. This can make it more difficult to focus your vision.

Perception is impaired after four drinks, when you have a BAC of .08%. Impaired perception makes it challenging to accurately judge distance and speed.

Substantial issues with visual and auditory processing set in at a BAC of .15%, or around seven alcoholic drinks4.

Reaction Time

Once your BAC is at .05%, you’ll have a slower response to emergency situations behind the wheel. If a car in front of you suddenly stops, for example, you may not hit the brakes in time if you’re impaired. At a BAC of .10%, reaction time is clearly and significantly limited5.

Research shows that the more complex a task is, the more alcohol slows reaction time6. This is true for even moderate amounts of alcohol. Driving decisions that must be made in a split second, like whether to swerve to avoid an obstacle, are far more challenging when intoxicated.


Alcohol impairs your coordination when you reach a BAC of .05%, or about three drinks. You may even find it difficult to steer properly. By four drinks, or a BAC of .08%, overall muscle coordination deteriorates. It’s difficult to balance, speak, and even hear as well as you normally do.

After about five drinks, braking appropriately is also challenging. At this point, limited coordination and balance make it difficult to maintain a safe position in your lane. When coordination, steering, braking, and correct lane position are limited, intoxicated drivers are a safety hazard for themselves and others7.


It’s well-known that alcohol negatively affects judgment. You may experience some loss of judgement after just two drinks, while significant impaired judgment occurs at a BAC of .08%. You may also experience a decline in your self-control and reasoning at this level of intoxication. Thinking becomes slower after five drinks, or a BAC of .10%8

Poor judgment can lead to speeding, running red lights, and other risky driving maneuvers. This is especially dangerous when your vision, coordination, and reaction time are also impaired.


Alcohol and aggression are closely linked, with alcohol intoxication being a factor in nearly half of all violent crimes9. Alcohol can alter the activity of the prefrontal cortex, which is linked to impulse control. This can increase the risk of rash behavior and reactive aggression.

Research shows a significant relationship between alcohol and both the perpetration and victimization of road rage10. The American Psychological Association (APA) states that people who experience road rage are more likely to misuse alcohol or drugs11. Aggression combined with impaired judgment and impulse control can be a recipe for road rage incidents.

Consequences of Drinking and Driving

timelapse of traffic on highway early morning
Photo by Joey Kyber on Unsplash

Over 10,000 people die each year in the U.S. from alcohol-related car crashes12. And every two minutes, someone is injured in a car accident involving alcohol13. Two of every three people will be impacted by a drunk driving crash at some point in their lifetime.

Deaths and injuries are the most severe outcomes of drinking and driving, but these aren’t the only potential consequences. In 2016, over one million drivers were arrested for driving under the influence (DUI)14.

DUI penalties range by severity and state, but it is a serious offense that no one wants to have on their record. Penalties can include losing your driver’s license, paying significant fines, or facing jail time. Even a first-time offense can cost more than $10,000 in fines and legal fees15.

Often, individuals charged with a DUI are also required to install an ignition interlock device at their own expense. This device requires drivers to blow into the interlock and register a BAC below .02% to start the car.

Drink Responsibly

If you’re drinking away from home, there are several steps you can take to ensure you’re drinking responsibly.

  • Plan to have a designated driver in advance.
  • Call a taxi, Uber, or Lyft.
  • Don’t let intoxicated friends get behind the wheel. Better yet, have an agreement with your friends that you’ll never allow each other to drive when intoxicated.

Support To Cut Back or Quit Drinking

Sometimes, sticking to responsible drinking plans isn’t easy. The right support can make all the difference.

Ria Health offers support for quitting or cutting back on alcohol. Our evidence-based program happens 100 percent online: You can access recovery coaching, support groups, anti-craving medication, and more, all from an app on your smartphone.

Learn more about how it works, or sign up for a free call to find out more about our program.


Ashley Cullins
Written By:
Freelance writer with contributions to numerous addiction blogs and a passion for relatable content.
Reviewed By:
Content Writer/Editor
Writer specializing in targeted, informative content. Dedicated to making the abstract accessible.

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