(3) The Minister of Transport, in the case of the preparation of a transportation plan, or the Minister of State for Urban Affairs, in the case of an urban development plan, or both Ministers in the case of the preparation of a transportation plan and an urban development plan in respect of the same transportation study area, may authorize payments from time to time under subsection 3(3) of the Act and these Regulations in respect of a portion of the preparation of the plan prior to the completion of the plan.