isochrone maps
... that isochrone maps have been used since 1972 or earlier, and that since 2009 online versions have been used by house hunters wishing to evaluate residential areas?
... that <b id="mwDjk"><a href="./Isochrone_map" id="mwDjo" rel="mw:WikiLink" title="Isochrone map">isochrone maps</a></b> <i id="mwDjs">(pictured)</i> have been used since 1972 or earlier, and that since 2009 online versions have been used by house hunters wishing to evaluate <a href="./Residential_area" id="mwDjw" rel="mw:WikiLink" title="Residential area">residential areas</a>?