§ 229. Pending grade crossing elimination proceedings. In connection with any proceedings for the elimination of a grade crossing in which all business and matters have not been completed on March first, nineteen hundred seventy-one, the commissioner may make any determinations; redeterminations; findings; amended, supplemental or revised findings; orders; or amended, supplemental or revised orders as he shall deem appropriate or necessary to carry out the duties and responsibilities of his office and may conduct such business hearings for such purposes as he shall deem appropriate.