R.I. Gen. Laws § 24-2-1: Creation of public highways by use.

All lands which have been or shall be quietly, peaceably, and actually used and improved and considered as public highways for the space of twenty (20) years, and which shall be declared by the town council of the town wherein they lie to be public highways, shall be taken and considered as public highways to all intents and purposes as fully and effectually as if the lands had been regularly laid out, recorded and opened by the town council of the town where the lands may lie.