What is the test for a child to be charged with contributory negligence in a motor vehicle accident?

2 Courtell v. McEachen, supra, 51 Cal.2d at 454, 334 P.2d at 873: 'The questions whether a child was capable of exercising care to avoid the particular danger encountered and whether, if so, the child failed to exercise due care, thereby contributing to the injury, are normally for the trier of fact to determine . . . . (C)ourts have rejected the theory that a child of plaintiff's age, namely, between five and six, is incapable of contributory negligence as a matter of law. (citation omitted)'

Mann v. Fairbourn, supra, 12 Utah 2d at 346, 366 P.2d at 606. "The question as to whether a child's capacity is such that it may be chargeable with contributory negligence is a question of fact for the jury, unless so young and immature as to require the court to judicially know that it could not contribute to its own injury or be responsible for its acts, or so old and mature that the court must know that, though an infant, yet it is responsible."