2006 New York Code - Obligation To Perform Service.

 
    §  20-512 Obligation to perform service. No person licensed under this
  subchapter shall refuse, without justifiable grounds, to  render  towing
  services  in  whole  or  in  part  to  a  person in charge of a disabled
  vehicle, other than a vehicle with a maximum  gross  vehicle  weight  of
  less  than  fifteen  thousand  pounds  that  is  involved in a vehicular
  accident, who has requested towing to a destination within the city. For
  purposes of this section, "justifiable grounds" shall include but not be
  limited to (a) the absence of an authorization by  the  commissioner  of
  transportation  or the police commissioner which is required to lawfully
  remove a vehicle from a specific location and (b)  an  authorization  by
  the  commissioner of transportation to provide only such towing services
  as may be specified by such commissioner to  remove  a  vehicle  from  a
  specific location.