In C4, C6, C7, C8, M1, M2 or M3 Districts, for public parking garages with more than 150 spaces, the City Planning Commission may permit modifications of the applicable regulations in Sections 33-26 to 33-30, inclusive, and Sections 43-26 to 43-31, inclusive, relative to rear yard regulations, provided the following findings are made:

(a)        that the public parking garage will alleviate excessive on-street parking demand and thereby relieve traffic congestion in the area; and

(b)        that because of site limitations such modification is necessary for the proper design and operation of the public parking garage.

The Commission shall consider the characteristics of surrounding development and may prescribe appropriate conditions and safeguards to minimize adverse effects on the character of adjacent areas.