R.I. Gen. Laws § 24-15-9: Rules and standards.

The board shall promulgate rules and establish standards for the maintenance, identification, construction, use, and preservation of the scenic highways system. The board may establish rules and standards for regulating and limiting the construction or establishment of a highway which is inconsistent with the purpose of this chapter. No rule or regulation may be adopted or promulgated which affects any provision of the general laws of the state or any federal statutory provision without the prior approval of the general assembly.