According to a report just released by the Drug Policy Alliance
, DUI arrests for defendants suspected of driving under the influence of marijuana have increased in the Denver area. This is not unexpected. There has been a great deal of attention devoted to Colorado and Amendment 64's legalization of recreational marijuana use. Lawyers, judges, law enforcement, probation officers, etc. are all more focused on the impact of Amendment 64. However, until these DUI defendants have actually had their respective days in court, we do not know if any of these people were actually under the influence at all. They have merely been arrested and accused.
One of the major issues in the debate surrounding marijuana legalization is how to quanitify intoxication by marijuana in a similar way to alcohol. In Colorado, if you are found to have a blood alcohol level of 0.08 mg/dl or greater, you are presumed to be under the influence of alcohol. Similarly, if you are found to have a blood THC level of 5 ng/ml, you are presumed to be under the influence of marijuana. However, there is a great deal of scientific evidence to suggest that people who use marijuana on a regular basis are not impaired in any way at this level. To be safe of course, you should not drive after the consumption of alcohol and/or drugs.