Legal recreational marijuana sales started in January 2014. That same month Colorado State Patrol started keeping track of driving under the influence arrests involving marijuana to try to spot any trends. Compared to 2014, 2015 saw a slight decrease, which I'm sure isn't welcomed news to marijuana opponents who predicted mayhem on the roadways once legal recreational marijuana sales began. Per the Durango Herald : Beginning in January 2014, Colorado State Patrol began tracking marijuana-related citations in an effort to identify trends. The data showed a 1.3 percent decrease from 2014 to 2015 for DUI and DUID citations involving marijuana. Out of 4,546 citations issued for DUI/DUID in 2015, there were 347 in which marijuana was the sole indicator, and 665 instances where marijuana was one of the indicators. But a mere two years of data collection doesn't point to a conclusion. "From those numbers, we know very little. They were released to provide insight," CSP Trooper Josh Lewis said. "We don't know if we're going to start seeing an increase or a decrease. When we get two, three, four more years of data, we'll find those first two years could be very different. We don't know what way it will be trending." How much do you want to bet that when there is 'two, three, four more years of data' that CSP Trooper Josh Lewis will be saying the same thing? I don't see why if there wasn't an increase from 2014 to 2015 that there all of a sudden will be down the road. But I guess time will ultimately tell. In the meantime, I will look at this as a good thing, and that legalized recreational sales don't result in a dramatic increase in DUIs involving marijuana.