How long does marijuana impair driving skills after smoking a single cigarette?

• A. 4-6 hours
• B. 1-2 hours
• C. 7-9 hours
• D. 10-12 hours

Answer: (A)

Marijuana impairs driving for several hours after a single cigarette because THC affects judgment, reaction time, coordination, and attention. After smoking, effects come on quickly and peak early, with noticeable impairment usually lasting about four to six hours. This makes the four-to-six-hour window the best description of typical impairment for a single use.

The shorter 1–2 hour range underestimates how long driving skills are affected for most people, while the longer ranges of seven to nine hours or ten to twelve hours exceed what’s commonly observed after one cigarette, though individual variation can occur. In practice, if you’ve used marijuana, it’s safest not to drive for several hours and to ensure any impairment has fully faded before getting behind the wheel.