Information:

The FAI rules specify a circle at 3 meters and another at 21 meters. This roughly correspond to a 10' radius and 69' radius.

I do not believe there are any specifications for AMA Speed events.

Regards,

Bill

Just paint one big 80' radius safety circle, no real need for anything else.

  I would look into the paint used for this. On the square pad at Buder, we had a big circle painted at the max perimeter, and another about 10ft diameter at the center with a 1ft dot in the middle. the dot got slippery in wet weather. And oddly enough, the asphalt cracked right along side the painted surfaces. Circles were about 3 or 4 inches wide and I think we had that done by a company that did parking lot and tennis court striping. The cracks were pretty serious in size. After the last resurfacing I think we changed up on that but don't remember the details. No center dot but some one did paint the 10ft and out diameter circles again and they are also cracking. I would consider dashed line spaced apart maybe. or look into specific paints. I remember we once marked our circles on a temporary site with dry wall strips for a contest. The highway department here uses some sort of tape for temporary lane changes for construction, and that may work out better. If good money was spent for the paving, no need to do anything that causes cracks, because that is the beginning of bigger problems over time.
  Type at you later,
  Dan McEntee