Before proceeding to sell any lots or plots as hereinbefore provided, the trustees of the association shall cause to be made and filed, as required by the provisions of acts relating to the making, recording and vacating of plats, a plat of the grounds belonging to said association, which shall indicate by numbers all lots or plots intended to be sold, and all parks, park lots or reserves of any character intended for common use, by letter or name. Such map shall also show by name all roadways or avenues laid out upon the grounds of the association, but such roadways and avenues shall in all respects, be deemed private ways, and only open to the public upon such conditions and restrictions and under such rules and regulations as the trustees shall prescribe.