Section 141. Orders, notices and service

Every  motor carrier operating
  pursuant to a certificate or permit issued under this chapter shall file
  with the commissioner a designation in writing  of  the  name  and  post
  office  address  of  a  person  upon whom or which service of notices or
  orders may be made. Such designation may from time to time be changed by
  like writing similarly filed. In default of such designation, service of
  any notice or order may  be  made  by  posting  in  the  office  of  the
  commissioner.  Whenever  notice  is given by mail as provided herein the
  date of mailing shall be considered as the time when notice is served.