R.I. Gen. Laws § 31-1-28: Types of traffic control devices.

(a) “Official traffic control devices” means all signs, signals, markings, and devices not inconsistent with chapters 1 — 27 of this title placed or erected by authority of a public body or official having jurisdiction, for the purpose of regulating, warning, or guiding traffic.

(b) “Railroad sign or signal” means any sign, signal, or device erected by authority of a public body or official or by a railroad and intended to give notice of the presence of railroad tracks or the approach of a railroad train.

(c) “Traffic control signs” means any device, whether manually, electrically, or mechanically operated, by which traffic is alternately directed to stop and to proceed.