So, how to map race tracks? Well, use highway=raceway but there’s a little more to it than that. not complicated, but the details can matter. This diary entry covers my own approach, which I think is a good one, but there’s always a chance of disagreement.
highway=raceway itself
Like any highway= tag, raceway is for a linear, possibly closed way. A closed raceway is not a polygon, as such usage would be difficult for data consumers to distinguish from an actual closed way such as an oval track. If you want to specify the width of a racetrack, there is a width tag. It does not seem widely used, but it is documented in the OSM wiki. It’s in meters, by the way. Specifying lanes=2 can be a reasonable thing for a Drag Strip as an alternative.
I only use highway=raceway for hot areas. Hot areas are the parts of the race track which are restricted to folks with special credentials - race and track officials, drivers, and designated crew. Regular ticker buyers are not permitted into these areas and most of them involve cars traveling at speed.
access roads and parking
For generalized access roads, highway=service is appropriate. For obvious reasons, use amenity=parking for the race paddock and any spectator parking. Use name to specify what type of parking and possibly designate specific purposes; Lime Rock Park and Thompson Speedway both have similar names for their two paddock spaces, the blindingly obvious “A Paddock” and “B Paddock”. The road from the end of a Drag Strip shutdown area back to the paddock is often referred to as a “return road” and that’s how I name them.
access
For operating race tracks access should probably be private, as a purchased or comped ticket, or official credentials are required for access.
oneway?
Most race tracks are oneway. Drag strips and ovals, always. You can tell which is the start end of the drag strip by the black burnout marks. US ovals are always run counter-clockwise, that is, you are always turning left.