California Vehicle Code 21058 exempts a physician traveling in response to an emergency call from California Vehicle Code § 22351 and 22352. Basically a doctor who displays an insigne can speed to a legitimate emergency. Although most hospitals in urban areas have doctors on staff at all hours, many rural hospitals do not.
If there is an emergency such as shooting victim, accident victim, woman in labor, etc the doctor may speed to his destination. The doctor cannot be reckless, because the law does not allow him to put others in danger. But in rural areas doctors may live 30 miles from hospital and they have to get to hospital in order to help patients.
It has to be an actual emergency and cannot be used for other purposes. Police officer may still pull over the physician to question an emergency and may follow him/her to a hospital to verify it. If you are charged with violating Cal. Veh. Code § 21058 you should contact Michalak Law Firm at 888.SHARK.40 or 323-828-0258. I will evaluate your case for free.