A 19-year-old driver is stopped with a BAC of 0.03%. Under zero tolerance laws, this driver:

Can lose their license, because drivers under 21 may not drive with a measurable BAC

Is legal, because the BAC is far below 0.08%

Only gets a warning on a first offense

Is legal if they are not carrying passengers

A police officer lawfully asks you to take a breath test after arresting you for DUI, and you refuse. What happens in most states?

Your license is suspended automatically under the implied consent law

Nothing, because the test is voluntary

You are allowed to take the test the next day instead

You pay a small fine and keep driving

Your adult passenger wants to drink from an opened bottle of beer while you drive. In most states this is:

Illegal, because open containers are not allowed in the passenger area

Legal, because the passenger is not driving

Legal if the passenger is 21 or older

Legal on highways but not in cities

Your doctor prescribes a medicine whose label warns that it may cause drowsiness. What should you do before driving?

Find out how it affects you and do not drive if it makes you drowsy

Drive normally, because a prescription drug is always legal

Drink coffee with it to cancel the effect

You live in a state where recreational marijuana is legal for adults. Driving while under its influence is:

Illegal, just like driving under the influence of alcohol

Legal, as long as you are 21 or older

Legal if you used it more than an hour ago

What happens when you combine alcohol with other drugs, such as cold medicine or sleeping pills?

The effects can multiply and impair you far more than either one alone

The drug cancels out the effect of the alcohol

Nothing changes if the medicine is sold without a prescription

You are less impaired because you drank less

Ahead of you, a car is weaving between lanes and braking for no reason. What is the safest response?

Keep well back and, when you can do so safely, call 911 or the police

Follow closely so you can read the license plate

Honk and flash your lights until it pulls over

Which of these can result from a DUI conviction?

License suspension or revocation

Fines, court costs and possible jail time

An ignition interlock device required on your vehicle

A driver aged 25 has a BAC of 0.06% and is driving dangerously. Can this driver be arrested for DUI?

Yes, because a driver can be charged if alcohol impairs their driving, even below 0.08%

No, because the BAC is below the legal limit

Only if the driver also has an open container

Alcohol and Drug Questions on the DMV Permit Test, With Answers

Alcohol and drug questions on the permit test check a handful of rules: the legal limit is 0.08% BAC for drivers 21 and older (0.05% in Utah), 0.04% for commercial drivers and near zero for drivers under 21. Only time lowers your BAC, any drug that impairs you is illegal to drive on, and refusing a chemical test brings an automatic suspension.

Updated on 2026-11-06 · Ver en español

DMVPermitUSA is an independent study tool. It is not affiliated with, endorsed by or operated by any state DMV, BMV, MVD, DPS or other government agency. Always check your state's official driver handbook and DMV website for current requirements.

Practice alcohol and drug questions · Take a full mock exam

For a driver aged 21 or older, what is the blood alcohol concentration (BAC) at which driving becomes illegal per se in almost every state? A. 0.10% / B. 0.05% / C. 0.08% / D. 0.02%. Answer: C. 0.08%. Every state sets the per se limit at 0.08% BAC for drivers 21 and older, except Utah, which lowered it to 0.05%. At or above the limit you are guilty of DUI even if you feel fine.
A 19-year-old driver is stopped with a BAC of 0.03%. Under zero tolerance laws, this driver: A. Is legal, because the BAC is far below 0.08% / B. Can lose their license, because drivers under 21 may not drive with a measurable BAC / C. Only gets a warning on a first offense / D. Is legal if they are not carrying passengers. Answer: B. Can lose their license, because drivers under 21 may not drive with a measurable BAC. All states have zero tolerance laws for drivers under 21, with a limit of 0.00% to 0.02% depending on the state. A 0.03% BAC brings a license suspension and other penalties.
What is the maximum BAC allowed when driving a commercial motor vehicle that requires a CDL? A. 0.04% / B. 0.06% / C. 0.08% / D. 0.10%. Answer: A. 0.04%. Federal FMCSA rules set a 0.04% limit for anyone operating a commercial motor vehicle. A CDL holder convicted of DUI, even in a personal car, also loses the CDL for at least one year.
You had several drinks at a party. What is the only thing that will lower your BAC before you drive? A. Drinking strong black coffee / B. Taking a cold shower / C. Exercising or walking it off / D. Waiting for time to pass. Answer: D. Waiting for time to pass. The liver removes alcohol at a fixed rate, roughly one standard drink per hour. Coffee, cold water and exercise may make you feel more awake, but they do not lower your BAC.
A police officer lawfully asks you to take a breath test after arresting you for DUI, and you refuse. What happens in most states? A. Nothing, because the test is voluntary / B. Your license is suspended automatically under the implied consent law / C. You are allowed to take the test the next day instead / D. You pay a small fine and keep driving. Answer: B. Your license is suspended automatically under the implied consent law. Under implied consent laws, getting a license means you agree to chemical testing when lawfully asked. Refusing leads to an automatic administrative suspension, often longer than for failing the test; the length varies by state.
Which driving skill does alcohol affect first, often before the driver notices any effect? A. Judgment and self-control / B. Hearing / C. The ability to read signs / D. Muscle strength. Answer: A. Judgment and self-control. Alcohol reaches the brain quickly and first weakens judgment and self-control, which is why drinkers often believe they are fine to drive. Reaction time, vision and coordination are affected next.
Which drink contains about the same amount of alcohol as a 12-ounce can of regular beer? A. A 16-ounce glass of wine / B. Two shots of 80-proof liquor / C. A 5-ounce glass of table wine / D. A 12-ounce glass of wine. Answer: C. A 5-ounce glass of table wine. A standard drink is about 12 ounces of regular beer, 5 ounces of wine or 1.5 ounces of 80-proof spirits. Mixed drinks and craft beers often contain more than one standard drink.
Your adult passenger wants to drink from an opened bottle of beer while you drive. In most states this is: A. Legal, because the passenger is not driving / B. Legal if the passenger is 21 or older / C. Legal on highways but not in cities / D. Illegal, because open containers are not allowed in the passenger area. Answer: D. Illegal, because open containers are not allowed in the passenger area. Most states ban open containers of alcohol in the passenger area of a vehicle, for drivers and passengers alike. An opened bottle should go in the trunk or behind the last upright seat; details vary by state.
Your doctor prescribes a medicine whose label warns that it may cause drowsiness. What should you do before driving? A. Drive normally, because a prescription drug is always legal / B. Find out how it affects you and do not drive if it makes you drowsy / C. Drink coffee with it to cancel the effect / D. Drive only on the highway. Answer: B. Find out how it affects you and do not drive if it makes you drowsy. DUI laws cover any substance that impairs your driving, including legal prescription and over-the-counter medicines. Read the label, ask your doctor or pharmacist, and do not drive if you feel drowsy or slow.
You live in a state where recreational marijuana is legal for adults. Driving while under its influence is: A. Legal, as long as you are 21 or older / B. Legal if you used it more than an hour ago / C. Illegal, just like driving under the influence of alcohol / D. Legal on private roads only. Answer: C. Illegal, just like driving under the influence of alcohol. Marijuana slows reaction time and affects judgment of time and distance. Driving while impaired by it is illegal in every state, whether or not the drug is legal to buy.
What happens when you combine alcohol with other drugs, such as cold medicine or sleeping pills? A. The effects can multiply and impair you far more than either one alone / B. The drug cancels out the effect of the alcohol / C. Nothing changes if the medicine is sold without a prescription / D. You are less impaired because you drank less. Answer: A. The effects can multiply and impair you far more than either one alone. Many drugs, especially those that cause drowsiness, multiply the effects of alcohol. A small amount of alcohol with a medicine can make driving very dangerous.
Two friends drink exactly the same amount in the same time. One weighs 120 pounds and the other 200 pounds. The lighter person will usually have: A. The same BAC / B. A higher BAC / C. A lower BAC / D. No measurable BAC. Answer: B. A higher BAC. BAC depends on how much you drink, how fast, your body weight and other factors such as food and sex. A smaller person has less body water to dilute the alcohol, so the same drinks produce a higher BAC.
Ahead of you, a car is weaving between lanes and braking for no reason. What is the safest response? A. Pass it quickly to get away / B. Follow closely so you can read the license plate / C. Keep well back and, when you can do so safely, call 911 or the police / D. Honk and flash your lights until it pulls over. Answer: C. Keep well back and, when you can do so safely, call 911 or the police. Weaving, drifting and erratic braking are common signs of an impaired driver. Keep a large space cushion, do not try to stop the driver yourself, and report the vehicle when it is safe to make the call.
Which of these can result from a DUI conviction? A. License suspension or revocation / B. Fines, court costs and possible jail time / C. An ignition interlock device required on your vehicle / D. All of the above. Answer: D. All of the above. DUI penalties vary by state and increase with each offense, but they can include all of these, plus mandatory alcohol education and much higher insurance rates.
A driver aged 25 has a BAC of 0.06% and is driving dangerously. Can this driver be arrested for DUI? A. Yes, because a driver can be charged if alcohol impairs their driving, even below 0.08% / B. No, because the BAC is below the legal limit / C. Only if a passenger complains / D. Only if the driver also has an open container. Answer: A. Yes, because a driver can be charged if alcohol impairs their driving, even below 0.08%. The 0.08% limit is the point at which DUI is automatic. Below it, you can still be charged if the officer has evidence that alcohol or drugs impaired your driving.

What alcohol and drug questions cover on the DMV test

Every state handbook has a chapter on alcohol, drugs and driving, and nearly every written test draws a few questions from it. They are some of the easiest points on the exam once you know the numbers, and some of the most expensive mistakes on the road: NHTSA counts alcohol-impaired crashes among the leading causes of traffic deaths in the U.S.

The questions fall into four groups. The legal limits: 0.08% BAC for drivers 21 and older in every state except Utah (0.05%), 0.04% for commercial drivers, and zero tolerance for drivers under 21. How alcohol works: what a standard drink is, what raises your BAC and why only time lowers it. Drugs: prescription, over-the-counter and illegal drugs, and marijuana. And the law: implied consent, open containers and the penalties for a DUI (called DWI or OWI in some states).

The rules behind the most-missed questions

Most wrong answers in this topic come from common myths. The questions are written to catch them, so learn the rule behind each one:

“I feel fine, so I can drive.” Alcohol weakens judgment first, so the person who has been drinking is the worst judge of their own impairment.
“Coffee will sober me up.” Only time lowers BAC. Plan a ride, a designated driver or a place to stay before you drink.
“Under 0.08% is always legal.” Drivers under 21 face zero tolerance, CDL drivers in a truck have a 0.04% limit, and any driver can be charged when impaired below 0.08%.
“My medicine is legal, so it is fine.” DUI laws cover any drug that impairs you, legal or not. Read labels for warnings such as “may cause drowsiness” or “do not operate heavy machinery.”
“I can refuse the test.” You can, but under implied consent the refusal itself triggers a suspension, and in many states it can be used as evidence in court.

Many states also have separate penalties for buying or possessing alcohol under 21, which can include losing your permit or license even when you were not driving. Check your state handbook for the exact rules.

How to study this topic

Memorize three numbers first: 0.08, 0.04 and your state's under-21 limit. Our BAC limits and DUI laws guide explains each one. Then learn the standard drink sizes (12 ounces of beer, 5 ounces of wine, 1.5 ounces of spirits) and the one-drink-per-hour rule of thumb. Most other questions in this topic can be answered by remembering that the law protects everyone on the road: when an answer choice lets an impaired person drive, it is wrong.

Next, read your state handbook's section on implied consent and penalties, because suspension lengths and the under-21 limit differ by state. Finish by mixing these questions with the rest of the exam on our topic practice tests, and check the related rules on licensing, points and suspensions.

Alcohol and drug test questions: FAQ

How many alcohol and drug questions are on the permit test?

It depends on the state and on the random set of questions you get, but most tests include at least one or two questions on BAC limits, alcohol's effects, drugs or DUI penalties. Some states, such as Florida, require a separate drug and alcohol course before a first license.

What is the legal BAC limit for drivers under 21?

Every state has a zero tolerance law for drivers under 21. The limit is 0.00%, 0.01% or 0.02% depending on the state, which in practice means you should not drink at all before driving.

Does implied consent apply to drugs as well as alcohol?

Yes. Implied consent laws usually cover breath, blood or urine tests for alcohol and drugs. The type of test and the penalties for refusal vary by state.

Can I drive after one drink?

If you are 21 or older, one drink may leave you below 0.08%, but alcohol affects judgment at any level and you can still be charged if you are impaired. If you are under 21, any measurable amount is illegal. The safest choice is not to drink before driving.

Is it legal to drive after using CBD or medical marijuana?

Having a medical marijuana card does not allow you to drive impaired. Driving under the influence of marijuana is illegal in every state. Products sold as CBD can also contain THC, so the same caution applies.