Ah, you're right I wasn't clear (it was early.) What I meant was, it's Uber's policy to charge a fee if a ride is canceled some amount of time after the driver accepts you as their fare. I think the grace period before the fee is about 2 min though I may be wrong. This my experience in New York and Boston.

I've never canceled a ride before waiting 5+ minutes and two of the three times I am referring to the driver drove past me twice.