Proceedings under this part and the adoption of such ordinance notwithstanding, the city and its legislative body shall retain its police powers and other rights and powers relating to the city streets constituting a part of the pedestrian mall. No action taken pursuant to this part shall be interpreted or construed to be a vacation or abandonment, in whole or in part, of any city street or any right therein, it being intended that the establishment of a pedestrian mall pursuant to this part be a matter of regulation only. Nothing in this part shall be interpreted or construed to prevent the city and its legislative body at any time subsequent to the adoption of the ordinance provided for in this chapter, from abandoning the operation of the pedestrian mall, from changing the extent of the pedestrian mall, or from changing or repealing any of the rules and regulations pertaining to the pedestrian mall but Section 11304 shall not operate as a bar to any claim of damages resulting solely from changes made subsequent to the adoption of the ordinance provided for in this chapter.