Alan Brown's History of America's Speedways documents more than 8000 race tracks in the US and Canada, of which fewer than 2000 are still in operation.
The Ghost Tracks on OpenHistoricalMap project is an effort to document the locations of old Racing venues. The NA Motorsports website provides a way to view the data collected and added to OpenHistoricalMap. The race track data in OpenHistoricalMap may be treated as public domain.
A YouTube channel has been created to present deeper dives into tracks
The oldest map inserts use overlaid imagery with a slider to control the transparency of the top image. This approach is being discontinued and the existing examples are going to migrate to the newer method, where track layouts are overlaid on an OpenStreetMap base map.