In Washington they argue that the 5ng test will put patients in danger of a DUI, in California they got patients to bring down prop 19 a few years back. The same is happening in Colorado.
The fact is no one is able to drive under the influence of marijuana. If they tested you today they would test for fat soluble cannabinoids that stay in your system for weeks. If you test positive and you haven't smoked in a week you have a possibility of getting a DUI. The new test will test for active cannabinoids and you usually only spike over 5ng for 2-6 hours depending how much you smoke.
Medical marijuana is becoming greedy and its time to move on. Plus they price their medicine 25%-50% higher than it should be.