It should be stronger than it is:
Researchers suggest that college students in general perceive stoned driving to be safe. The popular misconception is that, while alcohol demonstrably slows someone’s reflexes, marijuana makes drivers more anxious and, therefore, more attentive to possible mistakes on the road. But the research shows that, while marijuana doesn’t affect everyone in the same way, it does impair a person’s ability to drive at some level.
The Dish 