§ 710. Consolidation of proceedings. A justice before whom separate petitions to review assessments of real property are pending may on his own motion consolidate or order to be tried together two or more proceedings where the same grounds of review are asserted and a common question of law or fact is presented, except that a proceeding to review a special franchise assessment for the year nineteen hundred fifty-four or any year thereafter shall not be consolidated or ordered to be tried together with a proceeding to review a special franchise assessment for the year nineteen hundred fifty-three or any year prior thereto.