The Police Chief after consultation with the traffic engineer and the Fire Chief shall for public or semi public purposes have authority to close or restrict the use of any public street by vehicular or pedestrian traffic for any period not to exceed twenty-four (24) hours. For periods longer than twenty-four (24) hours, closure or restriction shall require approval by the Mayor or CAO, instead of the Police Chief, after consultation with the Police Chief, engineer and Fire Chief, and in either case shall be in writing and shall be effective only according to the terms stated therein. This Section shall not be construed in derogation of other general administrative powers of the City to control use of City streets.