www.youtube.com/watch?v=v-K1bvNw7Cw
It would seem to me that if an officer suspects me of consuming cannabis, I should have the right to just volunteer a blood sample. There should be no reason to force me to waste my time with unreliable tests once I volunteer for a blood sample. Once I volunteer a blood sample, the officer should legally be required to register my ID, take the blood sample, and let me go. If the officer is still concerned, he could drive me home. Other than that, he should let me go and let the blood test handle the rest.
Upto 3hrs after a joint is impaired driving. A blood sample can go back weeks if not months.
Go ahead, hang yourself.
A real Libertarian wouldn't say a word to a cop.