Section 239. Trains to come to full stop

All trains upon elevated railroads
  shall  come  to  a  full stop before any passenger shall be permitted to
  leave such trains; and no train on such railroad shall be  permitted  to
  start until every passenger desiring to depart therefrom shall have left
  the  train,  provided  such passenger has manifested his intention to so
  depart by moving toward or upon the platform of any car; nor until every
  passenger upon the platform or station at which such train has  stopped,
  and desiring to board or enter such cars, shall have actually boarded or
  entered the same, but no person shall be permitted to enter or board any
  train  after  due notice from an authorized employee of such corporation
  that such train is  full  and  that  no  more  passengers  can  be  then
  received.