Lawyer Q&A: Marijuana Laws
Q: “Since laws have passed in Colorado legalizing recreational marijuana use, is it OK to smoke and drive?”
A: The laws that govern smoking and driving are the same as the laws for drinking and driving. For those over 21, drinking alcohol and smoking pot may be legal, but when their use impairs or puts a driver under the influence it is a crime. There are ways of measuring the THC content of your blood. If there are active THC markers in your blood there is a good chance that your ability could be considered impaired. Right now with even a couple of nanograms you are believed to be impaired and over 5ng and they consider it to be under the influence. The District Attorney has expert witnesses that would testify to that relationship in court.
So just like drinking, one must wait until the marijuana has left your system before you operate a motor vehicle. The time that the effects of marijuana wear off vary between people just as alcohol does. It is best not to take chances and wait until it wears off. The police are trained to spot the effects and will not hesitate to write the ticket. If you do get a ticket, take it seriously. The blood tests can show THC levels for many days but not the active THC levels. Those wear off much more quickly and are what will cause impairment.