All the provisions of the Acts relating to hackney carriages and metropolitan stage carriages in force at the time of the commencement of this Act shall, subject to any alteration made therein by this Act or by any order or regulation of the said Secretary of State made in pursuance of this Act, continue in force, and all such provisions of the said Acts as relate to licences granted under those Acts, or any of them, shall, subject to any alteration as aforesaid, apply to licences granted under this Act.