Section 107. Long and short hauls

It  shall  be unlawful for any common
  carrier subject to the provisions of this chapter to charge  or  receive
  any  greater  compensation  in  the  aggregate for the transportation of
  passengers, or of like kind of property, for a shorter than for a longer
  distance over the same line or route in the same direction, the  shorter
  being  included  within  the  longer  distance, or to charge any greater
  compensation as a through rate than the aggregate  of  the  intermediate
  rates  subject  to the provisions of this chapter; but this shall not be
  construed as authorizing any common carrier  to  charge  or  receive  as
  great  compensation  for  a  shorter as for a longer distance; provided,
  however, that upon application to the commissioner such  common  carrier
  may  in  special  cases,  after  investigation,  be  authorized  by  the
  commissioner to charge less for longer than for  the  shorter  distances
  for  the  transportation of passengers or property; and the commissioner
  may from time to time prescribe the  extent  to  which  such  designated
  common  carrier  may  be  relieved  from  the operation of this section.
  Provided further, that any such carrier or  carriers  operating  over  a
  circuitous  line  or  route  may,  subject  only  to  the  standards  of
  lawfulness set forth in this chapter and without further  authorization,
  meet  the charges of such carrier or carriers of the same type operating
  over a more direct line or route, to or  from  the  competitive  points,
  provided  that  rates so established over circuitous routes shall not be
  evidence on the issue of the compensatory character of rates involved in
  other proceedings; and provided further, that  tariffs  proposing  rates
  subject  to  the provisions of this section requiring the commissioner's
  authorization may be filed when application is made to the  commissioner
  under  the  provisions  hereof,  and  in  the  event such application is
  approved, the commissioner shall permit such tariffs to become effective
  upon one day's notice.
    Whenever a carrier by railroad in competition with a  water  route  or
  routes  shall reduce the rates on the carriage of any species of freight
  to or from competitive points, it shall not  be  permitted  to  increase
  such  rates  unless  after hearing by the commissioner it shall be found
  that such proposed increase rests upon changed conditions other than the
  elimination of water competition.