Before granting a Special permit under sub-section (8) of section 88 of the Act the Transport Authority shall satisfy itself that such grant of Special permit shall not materially affect the purpose for which the original permit has been granted. If, however, such special permit is granted by any Transport Authority other than the one granting the original permit the Transport Authority which considers granting of the Special permit may obtain a No Objection Certificate " from the original permit granting Authority.