Section 509-H. Operation by person not licensed to drive a bus

The motor
  carrier shall not knowingly permit any person to operate a bus  carrying
  passengers  unless  the  driver  meets  all  of the requirements of this
  article; except that a motor carrier may permit a conditional school bus
  driver who is not otherwise disqualified under the  provisions  of  this
  article  to  operate  a  bus for a period not to exceed ninety days or a
  longer period if granted a written extension of such ninety  day  period
  by   the   department   pursuant   to  regulations  established  by  the
  commissioner. Such regulation shall authorize  extension  for  at  least
  that  period of time necessary to review information regarding the prior
  criminal history of the applicant.