Section 1171. Certain vehicles must stop at all railroad grade crossings

(a) The driver of any bus carrying passengers, of any school bus, of any
  motor vehicle with a gross vehicle weight rating  of  greater  than  ten
  thousand  pounds  that  transports  division  2.3 chlorine or is a cargo
  tank, whether loaded or empty, used to transport hazardous materials, as
  defined in section five hundred one-a of  this  chapter,  of  any  motor
  vehicle  required  to be marked or placarded by either the United States
  department of  transportation  or  the  New  York  state  department  of
  transportation  regulations or any vehicle carrying explosive substances
  or flammable liquids as a cargo or part of a cargo, of any  crawler-type
  tractor, steam shovel, derrick, roller, or of any equipment or structure
  having  a  normal  operating  speed  of  ten or less miles per hour or a
  vertical body or load clearance of less than one-half inch per  foot  of
  the distance between any two adjacent axles or in any event of less than
  nine  inches,  measured  above  the  level  surface of a roadway, before
  crossing at grade any track or tracks of a  railroad,  shall  stop  such
  vehicle  within  fifty  feet  but  not  less  than fifteen feet from the
  nearest rail of such railroad and while so stopped shall listen and look
  in both directions along such track for any approaching train,  and  for
  signals  indicating  the  approach  of  a  train,  except as hereinafter
  provided, and shall not  proceed  until  he  can  do  so  safely.  After
  stopping as required herein and upon proceeding when it is safe to do so
  the  driver  of  any  said  vehicle shall cross only in such gear of the
  vehicle that there  will  be  no  necessity  for  changing  gears  while
  traversing  such  crossing  and  the  driver shall not shift gears while
  crossing the track or tracks.
    (b) No stop need be made at any such crossing where a  police  officer
  or a traffic-control signal or sign directs traffic to proceed.
    (c)  Every  motor vehicle used in commerce with a gross vehicle weight
  rating  of  greater  than  ten  thousand  pounds  not  subject  to   the
  requirements  of  subdivision  (a)  of  this  section:  (i)  shall  upon
  approaching a railroad grade crossing, be driven  at  a  rate  of  speed
  which  will  permit said motor vehicle to be stopped before reaching the
  nearest rail of such crossing, and shall not be driven upon or over such
  crossing until due caution has been taken to ascertain that  the  course
  is  clear;  and  (ii)  shall  stop at such crossing if the course is not
  clear.
    (d) In addition to the requirements of subdivisions  (a)  and  (c)  of
  this   section,   the   driver   of  a  commercial  vehicle  must  check
  street-railway grade crossings within a business or residence district.
    (e) Notwithstanding any other provision of law, every  operator  of  a
  commercial  motor  vehicle  shall  obey  a traffic control device or the
  directions of a police officer at a railroad grade crossing.