Section 62. There shall be established and set up on the books of the commonwealth a fund to be known as the Transportation Infrastructure and Development Fund. The fund shall consist of monies transferred from the Gaming Revenue Fund and all other monies credited or transferred to the fund from any other fund or source and proceeds from the investment of such funds. The secretary of transportation shall be the trustee of this fund; provided, however, that no funds shall be expended until the secretary of administration and finance has provided written approval annually of a proposed spending plan. Any expenditures from this fund shall be solely for the purpose of transportation and related infrastructure projects including but not limited to, transit expansion and maintenance; provided, however, that not less than 50 per cent of such expenditures shall be dedicated for the purpose of supplementing, and not offsetting, any expenditures made for the construction and reconstruction of municipal ways as described in clause (b) of the second paragraph of section 4 of chapter 6C.