Today being 420 for stoners*, AutoInformed says don’t believe the rumors that marijuana won’t affect your driving. Driving impaired by any substance—alcohol or other drugs, whether legal or illegal—is against the law in all 50 states and the District of Columbia. Law enforcement officers are trained to observe a drivers’ behavior and to identify impaired drivers. Even in states where marijuana laws have changed, it is still illegal to drive under the influence of the drug. Research shows that marijuana impairs motor skills, lane tracking and cognitive functions.**