The traffic authority of any city or town may place and maintain traffic control signals, signs, markings, and other safety devices upon the highways under their jurisdiction as they may deem necessary to indicate and carry out the provisions of chapters 12 - 27 of this title, or local traffic ordinances or to regulate, warn or guide traffic, provided the signals, signs, markings, and devices conform to the regulations and specifications established by the state traffic commission in accordance with this chapter.
R.I. Gen. Laws § 31-13-3