((a)) ** .—** The Secretary of Transportation may—

((1)) issue and require the display of an identification plate on a motor vehicle used in transportation provided by a motor private carrier and a motor carrier of migrant workers subject to , except a motor contract carrier; and

((2)) require each of those motor private carriers and motor carriers of migrant workers to pay the reasonable cost of the plate.

((b)) ** .—** A motor private carrier or a motor carrier of migrant workers may use an identification plate only as authorized by the Secretary.