Section 45-22.1-4 - Preparation of comprehensive plan(a) Every joint municipal planning commission may prepare and maintain a comprehensive plan, in accordance with the provisions of this chapter, for the guidance of the continuing development of the area encompassed by the participating or member municipalities.(b) These plans and recommendations may be concerned with existing and proposed highways, public places, bridges and tunnels, viaducts, parks, parkways, recreation areas, sites for public buildings and structures, land use areas, building and zoning districts, waterways, routes of railroads and buses, location of sewers, water supplies and conduits, and other public utilities of the area.(c) The plans and recommendations are advisory and not mandatory for the communities.R.I. Gen. Laws § 45-22.1-4