N.Y. Gen. Bus. Law § 599-b

§ 599-b. Certificate of approval. Any person, firm, association or\ncorporation desiring a certificate of approval of any traffic control\ndevice not conforming to the current manual and specifications for a\nuniform system of traffic-control devices shall submit to the department\nof transportation one or more sets of each type of device for which\napproval is desired or such plans, specifications, design information or\ndata that the commissioner may require, in accordance with and together\nwith the fee provided by the rules and regulations promulgated by the\ncommissioner of transportation pursuant to this article. Upon a finding\nby the commissioner that the use of any such traffic-control device is\nnecessary, because there are no equivalent conforming devices, and\nbecause such use is consistent with the safe regulation of traffic on\nhighways within this state, he may issue a certificate of approval for\nthe sale, lease or offer for sale or hire of any such device.\n