What is the test for establishing a duty of care in a motor vehicle accident?

Assuming a duty of care is found to exist in a particular set of circumstances, the next step in the analysis requires a determination of the standard of care which must be met to discharge the duty in a particular case, Stewart v. Pettie (supra), at para. 35: ... The question of whether a duty of care exists is a question of the relationship between the parties, not a question of conduct. The question of what conduct is required to satisfy the duty is a question of the appropriate standard of care. The point is made by Fleming in his book The Law of Torts (8th ed. 1992), at pp, 105-106: The general standard of conduct required by law is a necessary complement of the legal concept of “duty”. There is not only the question “Did the defendant owe a duty to be careful?” but also “What precisely was required of him to discharge it?” Indeed, it is not uncommon to encounter formulations of the standard of care in terms of “duty”, as when it is asserted that a motorist is under a duty to keep a proper lookout or give a turn signal. But this method of expression is best avoided. In the first place, the duty issue is already sufficiently complex without fragmenting it further to cover an endless series of details of conduct. “Duty” is more appropriately reserved for the problem of whether the relation between the parties (like manufacturer and consumer or occupier and trespasser) warrants the imposition upon one of an obligation of care for the benefit of the other, and it is more convenient to deal with individual conduct in terms of the legal standard of what is required to meet that obligation. Secondly, it is apt to observe the division of functions between judge and jury. It is for the court to determine the existence of a duty relationship and to lay down in general terms the standard of care by which to measure the defendant’s conduct; it is for the jury to translate the general into a particular standard suitable for the case in hand and to decide whether that standard has been attained. [Footnotes omitted, highlighting added.]