Section 128A. A railroad corporation which has scheduled and operated a passenger train on a regular schedule for twelve consecutive months or more, except for holidays or interruptions caused by storms or other causes beyond its control, shall not discontinue the operation of such train or cut out more than ten per cent of its station stops, except with the written approval of the department after public hearing, notice of which hearing and proposed discontinuance shall be posted by the corporation at the stations involved for a period of fifteen days immediately preceding said public hearing. The department shall render a decision on its findings within a period of sixty days after said public hearing.