§ 101. Consent of commissioner of transportation in certain cases. No street surface railroad shall be allowed to lay its tracks at grade across the tracks or roadbed of any railroad operated by locomotive steam power at any point where there are three or more tracks of the steam road proposed to be crossed, which tracks have been constructed and in operation at least two years, unless the written consent of the commissioner of transportation be first obtained for such crossing at grade. But this section shall not affect the operation of the preceding section in any suit or proceeding pending on the twenty-ninth day of March, eighteen hundred and ninety-three, nor any renewals of said pending suit or proceeding brought for any cause.