BAC limit for drivers 21 and older
A free practice question for the Massachusetts permit test, with the answer explained.
Independent practice site. We're not the RMV and aren't connected to any government agency.
You are over 21 and driving your own car. At what BAC does driving become illegal?
The rule
A driver 21 or older is over the legal limit, and fails a chemical test, when the alcohol in their blood (BAC) is at 0.08 or above.
If you are 21 or older, driving with a BAC of 0.08% or more is over the legal limit. Drivers under 21 face penalties from 0.02%.
From the Massachusetts Driver's Manual, page 73. This question is our own wording of that rule. The handbook and the RMV have the final word.
Often mixed up with
People confuse these rules with this one. Each has its own practice question.
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