Dirt Oval Racing!!
When it comes to racing at our track, it was originally set up to accommodate 1/8th scale. So when running 1/10th scale, there is plenty of room for 10 or more cars without a lot of crashing. It is normal to run 12 4 wheel drive open cars for 5 minutes without anyone needing to be marshaled.
So I guess it would have to depend on the track size, car set up and how skilled the drivers are.