Alcohol and driving impairment

How does alcohol affect you while driving?

Alcohol decreases your attention. If you are drunk, you might not pay attention to traffic lights and road signs. Alcohol increases your reaction time. You might not react quickly to sudden events (e.g. a car stopping in front of you or a car suddenly coming in your lane). Alcohol also affects your ability to drive in lane. You might go in and out of lane. Some other effects of alcohol are:

You might not be able to track the road. If the road is winding, you might have difficulty keeping control of steering.

You might drive aggressively and in a risky way. You might drive too fast and over the speed limit.

You might have difficulty at intersections (traffic coming from all directions).

What else can make these problems worse?

Night time driving can make all of these problems worse.

Lack of sleep can make all of these problems worse.

Low blood sugar can make all of these problems worse.

Driving in tunnel or driving in hills can make all of these problems worse.

Distracted driving can make all of these problems worse. Talking on phone, texting, taking pictures while driving can be very dangerous.

Risk of serious reaction can be higher on days when you are tired, dehydrated, had a long day at work, did not get enough sleep, or did not eat well (read more about dangerous situations).

How many units of alcohol can you drink and drive?

Too much drinking increases your blood alcohol concentration (read more about blood alcohol concentration).

The more is your blood alcohol concentration, the more is risk of driving impairment.

Driving can be impaired at blood alcohol concentration of .03%

Just 2 drinks can take your blood alcohol concentration to .03%

That means you might not be able to drive safely after 2 drinks.

Got hangover. Okay to drive?

It is not okay. It is not safe to drive with hangover.

Marijuana, Pot, Weed with alcohol. Good or bad?

Marijuana with alcohol is bad combination. You have higher risk of driving problems

Amphetamines, Meth, Ecstasy, Molly with alcohol. Good or bad?

Stimulants (amphetamines, meth, ecstasy, Molly) with alcohol is a bad combination.

You might feel you are okay because you feel awake. You might think you are okay to drive. But you do not realize how drunk you are. Because your mind cannot tell you how drunk you are. Read more here.

The second problem is stimulants can make you drive in a risky way. You might drive aggressively. You might drive fast. You might not keep proper distance from car in front of you.

Marijuana and driving information from National Institute of Drug Abuse. Read here

Page last updated: 15-October-2019