Key points
Driving with a BAC of 0.08 percent or higher, or while under the influence of alcohol or drugs, is illegal.
Source: Handbook p. 115
“it is illegal for an individual to drive while under the influence of intoxicating liquor, narcotic, hallucinogenic or habit-producing drugs, or with a BAC of 0.08 percent or higher.”
New Jersey Driver Manual, Handbook p. 115If you are younger than 21, it is illegal to drive with a BAC of 0.01 percent or higher.
Source: Handbook p. 115
“For individuals younger than 21, it is illegal to drive with a BAC of 0.01 percent or higher.”
New Jersey Driver Manual, Handbook p. 115Crash risk doubles at a BAC slightly above 0.05 percent, is 6 times as great at 0.10 and 25 times as great at 0.15.
Source: Handbook p. 115
“If a motorist has reached a BAC of slightly above 0.05 percent after drinking, the risk for causing a motor vehicle crash doubles. The risk is six times as great when driving with a BAC of 0.10 percent. The risk is 25 times as great when driving with a BAC of 0.15 percent.”
New Jersey Driver Manual, Handbook p. 115After 2, 3 or 4 drinks, alcohol begins to impair reaction time, coordination and balance.
Source: Handbook p. 114
“After two, three or four drinks, alcohol begins to impair reaction time, coordination, and balance.”
New Jersey Driver Manual, Handbook p. 114Only time makes a person sober, because the body removes alcohol slowly.
Source: Handbook p. 114
“The only thing that can make a person sober is time. Alcohol is removed slowly by the body.”
New Jersey Driver Manual, Handbook p. 114A 12 ounce beer and a 5 ounce glass of wine hold the same amount of alcohol as a shot of whiskey.
Source: Handbook p. 115
“whiskey, 12 ounces of beer or 5 ounces of wine all contain the same amount of alcohol”
New Jersey Driver Manual, Handbook p. 115Your BAC depends on 4 things: how much you drink, your body weight, how fast you drink and the food you have eaten.
Source: Handbook p. 115
“BAC is determined by four factors: • Quantity of alcohol consumed • Body weight • How quickly drinks are consumed • Food eaten”
New Jersey Driver Manual, Handbook p. 115Refusing a breath test is illegal and brings its own penalties, including loss of driving privileges.
Source: Handbook p. 115
“Under state law, refusal to take a breath test is illegal. Penalties include loss of driving privileges”
New Jersey Driver Manual, Handbook p. 115If you use prescription drugs, you must show proof of the prescription to police if asked.
Source: Handbook p. 117
“If asked, motorists using prescription drugs must show proof of the prescription to law enforcement.”
New Jersey Driver Manual, Handbook p. 117After alcohol, marijuana is the drug most often found in drivers involved in crashes.
Source: Handbook p. 117
“After alcohol, marijuana is the drug most often found with drivers involved in crashes.”
New Jersey Driver Manual, Handbook p. 117
Numbers to know
| Number | What it means | Manual |
|---|---|---|
| 0.08% | BAC at which driving is illegal for adults | Handbook p. 115 |
| 0.01% (under 21) | BAC at which driving is illegal for drivers younger than 21 | Handbook p. 115 |
| 0.05% | BAC slightly above which crash risk doubles | Handbook p. 115 |
| 6 times at 0.10% | crash risk at a BAC of 0.10 percent | Handbook p. 115 |
| 25 times at 0.15% | crash risk at a BAC of 0.15 percent | Handbook p. 115 |
| 2, 3 or 4 drinks | when impairment of reaction time and balance begins | Handbook p. 114 |
| 1/2 ounce | alcohol in every drink | Handbook p. 114 |
| 12 ounces and 5 ounces | beer and wine servings with the same alcohol | Handbook p. 115 |
| 90 percent | share of alcohol burned up by the liver | Handbook p. 114 |
| 4 factors | what determines BAC | Handbook p. 115 |
| Over 40 | age after which to have your eyes checked every year | Handbook p. 118 |
3 questions from the New Jersey practice test
1. A New Jersey driver who is 21 or older has a BAC reading of 0.08 percent. What does that reading mean?
- It is below every alcohol-related limit
- It is legal unless the driver feels impaired
- It reaches the illegal adult threshold
- It triggers only a warning for a first stop
Show answer
It reaches the illegal adult threshold. For an adult motorist, New Jersey treats a BAC of 0.08 percent or higher as illegal, so a reading of exactly 0.08 percent reaches that threshold. It is not below every alcohol limit, and whether the driver feels impaired does not change a measured reading at the legal limit. The manual lists no warning only option for a first stop at that level. Impairment can begin well below 0.08, and a reading slightly above 0.05 percent already raises crash risk, so the safest plan is not to drive after drinking.
2. A New Jersey driver younger than 21 has a BAC of 0.01 percent. Is driving permitted?
- Yes, until the reading reaches 0.08 percent
- No, the under-21 threshold has already been reached
- Yes, when a supervising adult is in the vehicle
- Yes, if the trip is less than five miles
Show answer
No, the under-21 threshold has already been reached. New Jersey uses a much lower BAC threshold for a person younger than 21: 0.01 percent or higher is illegal. The adult figure of 0.08 percent belongs to a different age category and cannot be substituted here. A short trip and an accompanying adult do not create exceptions to the alcohol rule. The useful exam cue is the age phrase; once it appears, compare the reading with 0.01 percent before considering any adult standard.
3. After a driver reaches a BAC slightly above 0.05 percent, how does New Jersey describe the crash risk?
- It stays exactly the same
- It becomes six times as great immediately
- It doubles
- It falls if the driver ate first
Show answer
It doubles. The manual says crash risk doubles when a motorist reaches a BAC slightly above 0.05 percent. That figure describes increased danger, not a safe-driving threshold. Six times the risk is tied to a BAC of 0.10 percent, and eating does not make alcohol harmless. Separate risk figures from legal BAC limits because they answer different exam questions. No amount of confidence changes that measured risk.
Practice this topic
Lock it in with alcohol and dui questions from the free New Jersey practice test. Every answer comes with a plain English explanation.
Source: the New Jersey Driver Manual, Chapter 6: Drinking, Drugs, and Health. This lesson is a plain English summary, not the law itself; where it differs, the manual and the statute govern. Last checked 2026-09-27.