It shall be the duty of the Police Department to enforce the provisions of this Traffic Code. The Police Chief may assign such officers and members of the Police Department as he may determine necessary who shall, when so assigned, be charged with the specific duty of enforcing the provisions of this Traffic Code. In the event of fire or other emergency, or to expedite traffic or safeguard pedestrians, auxiliary police and civil defense personnel or members of the Fire Department may direct traffic as conditions may require, notwithstanding any other provisions of this Traffic Code.