R.I. Gen. Laws § 31-47-15: Exceptions.

This chapter shall not apply to any motor vehicle for the operation of which security or proof of financial responsibility is required to be furnished under §§ 39-14-18, 39-14-19, 39-13-7, 39-13-8, and 39-13-9, nor to any vehicle for which a permit or certificate is in force pursuant to the Interstate Commerce Act (see now 49 U.S.C. § 10101 et seq.), nor to any motor vehicle owned by the United States, any state, or any political subdivision of any state.