As a fan, which is where I believe the problem is, you could tell me there is a 100k to win pavement race that is going to have 70 cars and a 5k to win dirt race that is going to have 20 cars and I'm still going to the dirt track. Pavement racing is lackluster for the most part. Look across the board. NASCAR has cut the starting field size due to car counts. Indy car isn't what it used to be hardly any pavement series has a serious following. As far as certain pavement races having huge crowds, I'd be willing to bet a large percentage of them are dirt fans just attending for the experience(like the Indy 500). I actually had a friend who left the 500 early to get to haubstadt and watch a sprint car race. Even a great pavement race isn't as exciting as an average dirt race.