Dedicated public streets, walkways, alleys, accessways or easements may be closed or relocated as part of or in conjunction with any private development phase upon an application being made to the city council, after review of and recommendation from the planning and zoning board, and if the application is in the best interest of the city. However, the vacated land shall not be used as acreage for any density calculations. Any request for vacating a dedicated public street, walkway, alley, accessway or easement must be submitted no later than 30 days prior to the planning and zoning board meeting at which it is to be considered.