A person who, when driving or attempting to drive a motor vehicle on a road or other public place, is unfit to drive through drink or drugs shall be guilty of an offence.
Without prejudice to subsection (1) above, a person who, when in charge of a motor vehicle which is on a road or other public place, is unfit to drive through drink or drugs shall be guilty of an offence.
For the purposes of subsection (2) above a person shall be deemed not to have been in charge of a motor vehicle if he proves that at the material time the circumstances were such that there was no likelihood of his driving it so long as he remained unfit to drive through drink or drugs.
For the purposes of this section a person shall be taken to be unfit to drive if his ability to drive properly is for the time being impaired.
A constable may arrest without warrant a person committing an offence under this section.