Whether or not a violator is issued a summons is often determined by the violator's attitude or demeanor towards the LEO. A lot of people talk themselves into a ticket in lieu of a warning by being a jerk. Exceeding the speed limit by more than 10 mph is almost a guaranteed summons though.
This isn't true, at least in PA. If you get a speeding or traffic ticket (or other summary offense) you have ten days to respond and send in your payment with your guilty plea or request a trial in magisterial district court.
If the court doesn't receive your reply in those ten days a warrant will be issued for your arrest and the PA state police will come find you and you will be taken to jail.
How is this so hard to grasp?
EDIT: I'm not sure why I care. Speed; don't speed. Get a ticket; don't get a ticket. Deal with an out of state warrant or ignore it.
It's on you. Deal with the consequences of your actions.