(1) For this Act, a person is intoxicated if—
(a) the person's speech, balance, coordination or behaviour is noticeably affected; and
(b) it is reasonable in the circumstances to believe that the affected speech, balance, coordination or behaviour is the result of the consumption of—
(i) liquor; or
(ii) a drug; or
(iii) a combination of liquor and a drug.
(2) In this section:
"drug"—see the Road Transport (Alcohol and Drugs) Act 1977
, dictionary, definition of "drug", paragraphs (a) and (b).