Which of the following is the LEAST likely to be a sign that a driver is impaired by alcohol?
- Faster than usual reaction time. ✓
- A tendency to stare.
- Loss of peripheral vision.
- Loss of depth perception.
Answer: A. Faster than usual reaction time.
Faster than usual reaction time is the least likely sign of alcohol impairment, because alcohol slows reaction time rather than speeding it up.
Why this is the answer
The handbook describes a driver impaired by drugs or alcohol as one of the worst driving hazards, and gives the reason: these substances cause mental confusion and slow reaction times. A quicker-than-normal reaction time runs against that. The other choices describe losses or changes in what a driver takes in and how they respond, which fits the handbook's picture of a confused, slowed driver far better than a speeded-up reaction does.
Why the other answers are wrong
- B. A tendency to stare. — A tendency to stare does not conflict with the handbook's description of an impaired driver as mentally confused and slowed; it is a fixed, unresponsive way of taking in the road rather than a sharpening of reaction.
- C. Loss of peripheral vision. — Losing peripheral vision narrows what the driver can see, which fits the confused, less capable driver the handbook describes, while a faster reaction does not.
- D. Loss of depth perception. — Losing depth perception is a loss of a driving ability, in line with the handbook's point that impairment makes a person less able to judge and respond, so it is a more likely sign than a speeded-up reaction.
Remember it
Alcohol is a depressant: it takes abilities away and slows you down, so any sign of a driver getting sharper or quicker points away from alcohol.