As a general proposition it may be said that where a person driving an automobile at night observes persons walking along the public highway, it is the duty of the operator to manage it so as to avoid injuring the pedestrians if it is reasonably possible to do so, and the failure to use reasonable care to avoid such injury constitutes negligence on the part of the driver. Gideon v. Jones, 180 Okla. 621, 70 P.2d 814. Whether either the defendant or the deceased was negligent must be determined with reference to standards of conduct prescribed by law.