R.I. Gen. Laws § 46-25-43: Investment of receipt pending expenditures.

All moneys in the fund, not immediately required for payment pursuant to the provisions of this chapter, may be invested by the state investment commission, as established by chapter 10 of title 35, pursuant to the provisions of that chapter; provided, however, that the securities in which the fund is invested shall remain a part of the funds, as shall other securities for which the funds may from time to time, pursuant to that chapter, be exchanged, and provided, further, that the income from the investment shall become part of the fund, and shall be used to the extent possible to pay debt service costs.