The City Planning Commission may permit a development or enlargement on a zoning lot that includes either a railroad right-of-way or a former railroad right-of-way where the lot area is one and a half acres or greater, and may include a railroad right-of-way that would otherwise be considered a block boundary in the lot area of such zoning lot, provided the Commission finds that:

1. the distribution of floor area on the zoning lot does not adversely affect the character of the surrounding area by being unduly concentrated in any portion of such development or enlargement; and
2. where the zoning lot includes a former railroad right-of-way and a transportation agency has a plan to use such tract of land for transportation purposes, the site plan does not preclude future improvements to facilitate such transportation purposes. The Commission shall request the Metropolitan Transportation Authority and the Departments of Transportation of the State of New York and the City of New York to indicate within 30 days whether said agencies have any such plans.

On zoning lots of any size that require a certification pursuant to Section 75-411 (Developments on or over railroad rights-of-way), the Commission may permit the establishment of an appropriate level or levels instead of curb level, base plane, or other applicable reference plane, as the reference plane for the applicable regulations pertaining to, but not limited to, height and setback, floor area, lot coverage, open space, yards, and minimum distance between buildings.

The Commission may prescribe appropriate conditions and safeguards to minimize adverse effects on the character of the surrounding area.