It is unlawful for any parent, guardian, or person standing in the place of a parent or guardian, to knowingly permit any child under the age of 18 years to operate a skateboard in a negligent manner upon any roadway, sidewalk, publicly owned parking lot, other pedestrian or vehicular way open to the public whether publicly or privately owned, or other public property. (Ord. 1582 § 1 (part), 1990).