CNN continued its pursuit of journalistic excellence this month with a puff piece investigating the effects of marijuana on driving. The test took place in Washington, one of the two greenie states -- Colorado being the other -- that voted for the right to smoke in last year's election.

CNN tapped stoner Addy, a daily smoker, Dylan, a weekend user, and Jeff, an occasional user. CNN gave them three-tenths of a gram apiece to smoke before their first test. Driving-school instructor Mike Jackson -- the poor guy -- had to evaluate the potheads from inside the car while Thurston County police watched from the edge of the track. At the end of the first test, Jackson said he wouldn't have pulled any of the drivers off the road.

After the second smoking session, the subjects slowed down considerably. Jeff and Dylan were visibly affected, while Addy seemed about the same. Dylan went wide and had the wheel grabbed by the instructor, and he had trouble following the course.

After the third smoke, Addy was driving fast and, according to CNN, was “just excited about being high and behind the wheel.”

She made no major mistakes.

Following the driving tests, CNN brought all three subjects into the police station to test for impairment. All three of them failed, and they would have been charged for driving under the influence had they not been participating in an experiment. All three also said they would have opted not to get behind the wheel were they not instructed.

The legal limit in Washington is 5 nanograms. After the first smoke, all three participants were well over that. In fact, Addy was over when she arrived.

Of course, all of this talk of limits is more or less irrelevant where marijuana use remains criminalized. If the legalization ever does go country-wide, however, we wouldn't be entirely surprised if a zero-tolerance law were enacted -- as CNN's experiment shows, the impact of marijuana use varies dramatically from driver to driver.