Have you tried? I've certainly been able to. And I'm definitely not alone in having used those facilities. I've used them personally and for ad-hoc sport events (lacrosse isn't exactly popular in the area I'm in right now).
Not recently, though I have observed locked doors and gates that make it pretty difficult to use. If your caveat is you need to call ahead to organize an event that's a pretty different use-case from what I'd like to do, which is to use them very casually and occasionally.
Not recently, though I have observed locked doors and gates that make it pretty difficult to use. If your caveat is you need to call ahead to organize an event that's a pretty different use-case from what I'd like to do, which is to use them very casually and occasionally.