i’ve started working on adding Auto Racing venues in the US & Canada to the map, and improving those that are already in the map.
this exercise is in two parts; for those tracks that are still clearly visible (active or inactive) i will add the tracks to OSM. For those which are more doubtful, or which will never return to service, i am adding them to OHM. Examples of the latter include tracks like the first and second circuits at Watkins Glen. hopefully, when the site of an inactive track is redeveloped, we’ll reach a state where instead of deleting tracks, they get moved to OHM.
for tagging, i am mostly using ways with highway=raceway. if a direction is discernible (ovals are usually counter clockwise), i set oneway as well. I try to identify the bounding area for the facility and create a landuse=recreation_ground poly with the name and address of the site.
I have largely completed Alaska, am currently nearly done with Arizona, and have also done several examples of historic tracks in upstate New York. i will be working on the south and southwest for the time being, as that is where people are racing at this time of year.
in Arizona i have seen a couple of examples where the race track was done as a multi polygon relation tagged as leisure=track. this tag is for non-motorized racing, not for auto racing. although in the 20s and 30s there were some dual purpose tracks (horses and cars), this practice was abandoned before WWII. i am changing the tags to highway=raceway, but the current mapnik style sheet doesn’t render highway=raceway on relations, so as a temporary expedient i am adding ways in the center, which i will go back and remove when the style sheet is updates (and yes, there is a tracker on this in the mapnik queue).
i have a leaflet example of an OHM/OSM mashup here showing the modern Watkins Glen circuit (the 4th circuit) overlaid with the OHM representation of the 2nd Watkins Glen circuit (the first Glen circuit is up and to the right): http://www.na-motorsports.com/test/test.html