R.I. Gen. Laws § 31-1-27: Business and residence districts.

(a) “Business district” means the territory contiguous to and including a highway when within any six hundred feet (600′) along that highway there are buildings in use for business or industrial purposes, including but not limited to hotels, banks or office buildings, railroad stations, and public buildings which occupy at least three hundred feet (300′) of frontage on one side or three hundred feet (300′) collectively on both sides of the highway.

(b) “Residence district” means the territory, contiguous to and including a highway but not comprising a business district, when for a distance of three hundred feet (300′) or more the property is in the main improved with residences or residences and buildings in use for business.