On 11/01/2011 17:57, DavidD wrote: > The mapnik layer already renders highway=track;surfaced=paved as a > solid line and highway=track;surface=unpaved as a dashed line. > > An example > http://osm.org/go/eutNf8ah-- That is rendering the different tracktype tags (grade1/grade2 etc), not the surface tags. I don't think Mapnik renders the surface tags at all.