Now that a few more states have legalized certain limits of marijuana, driving while high is going to become an issue. Police pretty much already know how to pick out a drunk driver. Slurred speech, mood swings, swerving on the road. But how do the police tell if someone is driving over the limit when it comes to weed?? Colorado and Washington state both recently legalized marijuana, up to certain amounts. So what someone did was setup a drivers test and purposely had 3 people smoke weed prior to driving to see how they would do. The results may surprise some of you. Check out the video after the jump.