Published: Friday, March 18, 2011 11:17 PM EDT

As if Michigan’s medical marijuana law wasn’t hazy enough, a recent statement by Attorney General Bill Schuette and a decision by two Traverse City judges make the situation even more confusing.

According to an article by the Associated Press, Schuette is urging the state appeals court to reverse a decision that could help a medical-marijuana user beat a driving offense.

The article states two judges have refused to instruct a jury that way in the case of Rodney Koon, who was charged last year with driving while under the influence of drugs. He has a medical-marijuana card and admitted he smoked pot before being stopped for speeding. A blood test confirmed it, but Koon claims he smoked the marijuana six hours before driving and he was no longer under its influence.

The case is on hold while the Grand Traverse County prosecutor appeals a decision that requires him to prove that marijuana actually impaired Koon.

Schuette says the Traverse City judges are misinterpreting the medical-marijuana law, and that any marijuana in a driver’s body is a crime.

Medical marijuana advocates argue Schuette’s interpretation of the law is unreasonable because THC, the a main psychoactive chemical in marijuana, remains in the body for weeks, even though the user is no longer impaired.

If the Traverse City prosecutor wins his appeal, the ruling could, in effect, make it illegal for anyone who has smoked marijuana in the last month to drive — even if that marijuana was smoked legally under the medical marijuana law. Advocates are correct; that would be unfair.

On the other hand, Michigan drivers cannot be put at risk by a ruling that would give high people the OK to drive. Since there’s no test for police to determine with accuracy whether a person actually is impaired by marijuana or just has residual THC in his or her body, the ruling could get guilty drivers off the hook.

There’s no easy solution for this problem, but it’s clear legislators need to take another look at the law.

In January, Rep. Claire Levy, a Colorado lawmaker, sponsored a bill that would set a DUI limit for marijuana, according to an article by CBS in Denver, Colo. The bill would allow police to do a blood test for THC, and it would equate 5 nanograms of the chemical with a blood alcohol level of .08, which is the legal limit.

Whether Levy’s bill is the correct solution is debatable, but something needs to be done to clear up this law. Right now, patients and police are at risk of making mistakes because they simply don’t know the correct course of action.