(1) A person commits an offence if, when in charge of a mechanically propelled vehicle in a public place with intent to drive or attempt to drive the vehicle (but not driving or attempting to drive it), he or she is under the influence of an intoxicant to such an extent as to be incapable of having proper control of the vehicle.

(1A) A person, other than a person referred to in subsection (1B), commits an offence if, when in charge of a mechanically propelled vehicle in a public place with intent to drive or attempt to drive the vehicle (but not driving or attempting to drive it), there is present in his or her body a quantity of a drug specified in column (2) of the Schedule such that, within 3 hours after so being in charge, the concentration of that drug in his or her blood is equal to or greater than the concentration specified in column (3) at the same reference number.

(1B) Subsection (1A) does not apply to a person in respect of a drug specified at reference number 1 or 2 in column (2) of the Schedule where the person is the holder of a medical exemption certificate which indicates that at the time at which that drug was found to be present in his or her blood it had been lawfully prescribed for him or her and which is signed by the doctor who prescribed it.