This report is simply reefer madness, designed to make the public scared of those who use marijuana.  In today's version of the classic fear-mongering film, you won't be murdered by s psychotic MJ user, he/shevwill simply drive a car into innocent people and kill them that way!  NO WAY DENVER POST, FAKE NEWS!  The mere presence of MJ in a person's urine (and I should not have to say this) is NOT an indication that person was impaired at the time of the accident.  It takes weeks for marijuana to process out of the human body, whereas alcohol will be gone in 24 hours.  I do agree that it's alarming that traffic fatalities have risen in Co, but let's not rush to assume that is due to the legalization of marijuana.  Perhaps it's due to increased population in Co, and crowded roads?  The reason more people test positive for MJ is because it has been legalized for personal use in CO.  The increased % of the population testing positive is just a reflection of its legal status only.