Click the map to place corners, then Finish. Drag any handle
to reshape; click a dashed midpoint to add a corner; right-click a
corner to remove it.
Streets are compiled from every source available for the area and
de-duplicated, so a road two sources both have is counted once. The
console reports what each source contributed.
These are mathematically generated grids anchored at an arbitrary
coordinate. The fiber follows their streets exactly, but those
streets are invented and will not match the basemap underneath.