What constitutes an affirmative declaration of duty in a motor vehicle accident?

"An affirmative declaration of duty simply amounts to a statement that two parties stand in such relationship that the law will impose on one a responsibility for the exercise of care toward the other. Inherent in this simple description are various and sometimes delicate policy judgments. The social utility of the activity out of which the injury arises, compared with the risks involved in its conduct; the kind of person with whom the actor is dealing; the workability of a rule of care, especially in terms of the parties' relative ability to adopt practical means of preventing injury; the relative ability of the parties to bear the financial burden of injury and the availability of means by which the loss may be shifted or spread; the body of statutes and judicial precedents which color the parties' relationship; the prophylactic effect of a rule of liability; * * * and finally, the moral imperatives which judges share with their fellow citizens--such are the factors which play a role in the determination of duty." (Raymond v. Paradise Unified School Dist., 218 Cal.App.2d 1, 8, 31 Cal.Rptr. 847, 851.)