When two or more uses, activities, or separate establishments are located within the same development, off-street parking as required for each use, activity, or separate establishment pursuant to § 224-64C may be reduced by a total of 20% in the aggregate pursuant to a shared parking plan which the proponent of the development shall submit to the City Engineer for review and approval in accordance with the standards set forth by authoritative sources such as the Institute of Transportation Engineers (ITE) and/or the Urban Land Institute (ULI). Any such shared parking plan shall be prepared by a professional engineer licensed as such by the Commonwealth of Pennsylvania who shall regularly practice in the field of traffic study and design and shall include consideration of (i) the hours of operation of the uses, activities, or separate establishments are located within the development; (ii) the location and proximity of off-street parking spaces within the development relative to each of those uses, activities, or separate establishments; (iii) the expected duration of the stay at the subject development by visitors to each use, activity, or separate establishment; and (iv) the relative sizes of each use.