§ 29. Official map, changes. Such legislative body is authorized and empowered, whenever and as often as it may deem it for the public interest, to change or add to the official map of the city so as to lay out new streets, highways or parks, or to widen or close existing streets, highways or parks. Drainage systems may also be shown on this map. At least five days' notice of a public hearing on any proposed action with reference to such change in the official map shall be published at least once in an official publication of said city or in a newspaper of general circulation therein. No change in the official map shall be made for the lay out of a new street or the opening or widening of any street unless notice shall have been sent by registered mail, return receipt requested, to the person and address noted on the last preceding real property tax notice issued on the property which is to be included in such proposed layout, opening or widening of such streets. Before making such addition or change the matter shall be referred to the planning board for report thereon, but if the planning board shall not make its report within thirty days of such reference, it shall forfeit the right further to suspend action. Such additions and changes when adopted shall become a part of the official map of the city, and shall be deemed to be final and conclusive with respect to the location of the streets, highways and parks shown thereon.

The layout, widening or closing, or the approval of the layout, widening or closing of streets, highways or parks by the city under provisions of law other than those contained in this article shall be deemed to be a change or addition to the official map, and shall be subject to all the provisions of this article.