At least thirty days before proceeding under any other of the provisions of this subheading, after the popular approval of the loan hereinbefore mentioned, if so approved, said Mayor and City Council of Baltimore shall file in the office of the County Commissioners of Baltimore County, one or more maps showing the existing roads and highways, traversing the property to be acquired under this subheading, both public and private, which are to be closed, altered, divided or relocated, in whole or in part, or the grades thereof changed; and also to show all roads or parts of roads which the Mayor and City Council of Baltimore propose to construct in substitution for, or to take the place of any such roads so closed, obstructed, altered or changed. P.L.L., 1915, §826LL 1927, §826N 1930, §826N 1938, §1050 1949, §654 1969, §25-13 1908, ch. 214