Rules and conditions
Do not drive when a medication or drug impairs safe driving, even if it was legally prescribed. Legality of possession does not guarantee unimpaired perception, judgment, or reaction. A BAC below the numerical legal limit does not establish that driving is safe or exclude impairment-based DUI consequences. Impairment is a functional safety issue, not a permission granted by a low numerical reading. In an ordinary passenger car, store an open alcohol container in the trunk or another permitted non-passenger area, not the glove box. Closing the glove box does not convert an open container into a sealed one. The handbook lists 0.01% BAC as an illegal threshold for drivers under 21. The under-21 rule must not be replaced with the ordinary adult threshold.
Worked comparison
For example, a prescribed medicine makes a driver drowsy. The defensible response is: Arrange another safe way to travel. Compare this with the mistaken proposal: Drive because only illegal drugs are covered by DUI rules. Legality of possession does not guarantee unimpaired perception, judgment, or reaction. For example, a driver feels impaired despite a BAC below the usual adult limit. The defensible response is: Arrange other transport if alcohol is impairing safe vehicle control. Compare this with the mistaken proposal: Treat every below-limit reading as a safety guarantee. Impairment is a functional safety issue, not a permission granted by a low numerical reading.
Transfer and self-check
Compare three questions: Is the person impaired? Which BAC rule applies? Where may an opened container be carried? Keep these questions separate. Explain why a legal prescription, a below-limit reading, or a closed glove box does not automatically resolve the relevant rule.
A prescribed medicine makes a driver drowsy. Which response follows the applicable California handbook rule?
- Identify the relevant condition: A prescribed medicine makes a driver drowsy.
- Do not drive when a medication or drug impairs safe driving, even if it was legally prescribed.
- Legality of possession does not guarantee unimpaired perception, judgment, or reaction.
Compare the other answer choices
The proposal "Drive because only illegal drugs are covered by DUI rules." conflicts with this applicable condition: Do not drive when a medication or drug impairs safe driving, even if it was legally prescribed. It does not resolve the stated risk: Legality of possession does not guarantee unimpaired perception, judgment, or reaction.
The proposal "Drive faster to reduce the time spent on the road." conflicts with this applicable condition: Do not drive when a medication or drug impairs safe driving, even if it was legally prescribed. It does not resolve the stated risk: Legality of possession does not guarantee unimpaired perception, judgment, or reaction.
The proposal "Ignore the warning if no alcohol was consumed." conflicts with this applicable condition: Do not drive when a medication or drug impairs safe driving, even if it was legally prescribed. It does not resolve the stated risk: Legality of possession does not guarantee unimpaired perception, judgment, or reaction.
Try it, then explain it.
Complete a short set without looking at the example. After each answer, explain which evidence or rule supports your decision and why the alternatives do not fit.
Sources & authorship
Original Slope explanations and examples. References support the concepts; they are not the source of copied questions. Independent educator review is pending.
California DMV alcohol and drugs