R.I. Gen. Laws § 31-32-20: Alternate methods of giving proof.

Proof of financial responsibility when required under this chapter, with respect to a vehicle or with respect to a person who is not the owner of a vehicle, may be given by filing:

(1) A certificate of insurance as provided in § 31-32-21 or 31-32-22;

(2) A bond as provided in 31-32-27;

(3) A certificate of deposit of money or securities as provided in § 31-32-30;

(4) A certificate of self-insurance, as provided in § 31-33-9, supplemented by an agreement by the self-insurer that, with respect to accidents occurring while the certificate is in force, the self-insurer will pay the same amounts that an insurer would have been obliged to pay under an owner’s motor vehicle liability policy if it had issued a policy to the self-insurer.