Christian Science Monitor:  “As states liberalize their marijuana laws, public officials and safety advocates worry that more drivers high on pot will lead to a big increase in traffic deaths. Researchers who have studied the issue, though, are divided on the question.  Studies of marijuana’s effects show that the drug can slow decision-making, decrease peripheral vision and impede multitasking, all of which are critical driving skills. But unlike with alcohol, drivers high on pot tend to be aware that they are impaired and they try to compensate by driving slowly, avoiding risky actions such as passing other cars, and allowing extra room between vehicles.”