What is the implied consent test for a driver?

In considering the test set out by Milvain C.J.T.D. in Palsky v. Humphrey, Spence J. stated at p. 39: “In his reasons for judgment, the learned trial judge had said: “ ‘It is my conception of the meaning of that statute that in dealing with the implied consent it means that one must approach the problem in a somewhat subjective fashion from the point of view of the person who was driving. That is to say whether under all of the circumstances the person, who was driving, would have been justified in deeming that he had an implied consent to drive.’ ”