The City Council has determined that the use of skateboards on certain public streets and sidewalks within the city has created a hazard for pedestrian traffic, motor vehicular traffic, and to the individuals themselves who are using skateboards, especially on certain streets within the city as hereinafter designated which have heavy vehicular and pedestrian traffic. The City Council further finds that in order to avoid this hazardous condition and to eliminate as soon as possible the potential for accidents and serious injury to the public and to skateboarders themselves, it is necessary to adopt this subchapter.