A. The provisions of this Title regulating the operation, parking and standing of vehicles shall not apply to any vehicle that has qualified under the Vehicle Code as an authorized emergency vehicle, when any such vehicle is operated in the manner specified in the Vehicle Code in response to an emergency call.
B. The foregoing exemption shall not, however, protect the driver of any such vehicle from the consequences of his willful disregard of the safety of others.
C. The provisions of this Title regulating parking or standing of vehicles shall not apply to any vehicle of the City or of the State Department of Transportation, while necessarily in use for the construction, repair work, survey work or traffic engineering investigations on any highway or any vehicle owned by the United States while in use for the collection, transportation or delivery of the United States mail.