Section 38. The county commissioners, aldermen or selectmen or road commissioners may purchase or select and lay out land within their respective counties, cities or towns, not appropriated to public uses or owned by any other town, from which may be taken materials necessary for the construction, repair or improvement of public ways; and may lay out such ways as they consider necessary for convenient access thereto. All proceedings relative to such land and ways shall be the same as are provided in the laying out of other ways, and if it is necessary to acquire land for the purposes of this section, the same may be taken by eminent domain under chapter seventy-nine.