(a) Upon designation of Council of a Permit Parking District, the Department of Streets shall erect signs which shall be of such a character as to inform an ordinarily observant person of the restrictions, but only on those blocks of a street on which at least one resident of each of at least fifty-one (51%) percent of the dwelling units has completed a formal petition for designation of the block as a residential permit parking block.

(b) Residents of any block which is designated and posted for residential permit parking may elect to remove the designation and the signs if at least one resident of each of at least fifty-one (51%) percent of the dwelling units located on that block has completed a formal petition for such removal.

(c) When a block has no residents, and commercial and/or institutional use of the property on the block does not exceed fifty (50%) percent, the Department of Streets, or its designee, can make a determination whether or not to post the block based on a consideration of parking needs in the area.