In a large-scale community facility development containing hospitals or functionally related facilities in Manhattan Community Board 12, when the air space above a wide street, or portion thereof, is closed and demapped, the City Planning Commission may, by special permit, allow the development in such demapped air space of an enclosed bridge or bridges to connect buildings within the large-scale community facility development. As a condition for granting a permit for development of such bridges, the Commission shall find that:

(a)        such bridge or bridges are essential to internal circulation of the medical function of the health care facility;

(b)        such bridge or bridges shall not rest upon columns or other supports which intrude upon the street;

(c)        the width of each such bridge shall not exceed 20 feet;

(d)        such bridge within the demapped air space utilizes only floor area derived from the adjoining zoning lots and that no floor area credit is generated from the demapped air space;

(e)        illumination of at least five foot candles is provided at the curb level of such bridge or bridges;

(f)        such bridge in demapped air space over a wide street adjoins zoning lots wholly within the large-scale community facility development;

(g)        the minimum horizontal distance between the nearest edges of two such bridges traversing the same street shall be two times the width of the street;

(h)        the maximum exterior height of each such bridge shall not exceed 12 feet;

(i)        the benefit gained from the bridge or bridges resulting from the bulk design or placement of such bridge or bridges outweighs any adverse impact on neighborhood character and any restriction of access to light and air to surrounding public spaces and streets; and

(j)        a landscaped open area for public use at street level, linked with the pedestrian circulation system, which is at least equivalent to the street area covered by the bridge is provided in one location within the large-scale community facility development and such open area is maintained with planting and seating facilities by the owner of the large-scale community facility development or the owner's designee.

The City Planning Commission may prescribe appropriate conditions and safeguards to minimize the effect of the bridges, including but not limited to clearance above the street and surfacing materials of the bridge.