Cependant, d'après les études menées par Robbe en Hollande, les fumeurs de marijuana se concentraient davantage sur la conduite, ils conduisaient plus lentement et étaient plus vigilants.
However, the Robbe studies from Holland indicated that marijuana smokers paid more attention to their driving, that they slowed down and were more aware of the situation and that they did not take the kinds of risks that people take under alcohol.