R.I. Gen. Laws § 31-14-5
Whenever local authorities within their respective jurisdictions determine upon the basis of an engineering and traffic investigation that the prima facie speed permitted under this chapter at any intersection or local street within a business or residence districts is greater than is reasonable or safe under the conditions found to exist at the intersection, or local street within business or residence districts, the local authority, subject to § 31-14-8, shall determine and declare a reasonable and safe prima facie speed limit at that place, which shall be effective at all times or during hours of daylight or darkness or at any other times that may be determined when appropriate signs giving notice of it are erected at the intersection or local street within a business or residence district or at its approaches.
R.I. Gen. Laws § 31-14-5