Impaired Driving en No Consensus On Marijuana Blood Tests <p>Arrests and prosecutions for driving under the influence of marijuana do not appear to be going up or down. Voters legalized recreational marijuana as of December sixth, and set a strict new standard for how much marijuana can be in your blood, if you're stopped for impaired driving. Thu, 07 Feb 2013 14:30:28 +0000 Keith Seinfeld 22369 at