From what I read, this particular velodrome has a release form, they even have bikes to use there and encourage those interested to schedule a session:

http://www.sfdj.com/sun_sprt/vpage1.htm
http://miamibikescene.blogspot.com/2...velodrome.html

That 2nd link, the track doesn't look terribly crowded for traffic, very much like a track & field for runners, but obviously the cycling has to be more dangerous. It's actually quite interesting, communities build these meccas to some type of health & fitness and they eventually wind up under or unused.