The state is taking the first steps towards deciding exactly when a driver is under the influence of marijuana.
Michigan's Medical Marijuana law says drivers can not be prosecuted unless they're under the influence.
A bill passed by the house today would create a commission to determine the level of T.H.C. in the body that would be considered evidence of impaired driving.
"T.H.C. is the component of marijuana that makes users high.
The problem is it can stay in the body long after the effects have worn off.
