The effects of cannabis on driving have been extensively studied for decades. Research consistently shows that typical cannabis use causes very little or no impairment to driving ability.
A new study from the National Highway Traffic Safety Administration finds that drivers who use marijuana are at a significantly lower risk for a crash than drivers who use alcohol.
An Arizona appeals court has ruled that marijuana users don't need to be actually impaired to be successfully prosecuted for driving under the influence. The common sense-defying ruling came Tuesday in the case of a man who tested positive for an inactive marijuana metabolite that remains in the body for weeks after the high from smoking marijuana has worn off.