For the speeding ticket, if the police officer stops you, you'd get a ticket and would sign it, thus ensuring you were there. Or, if you refuse, the police officer would testify in court (if you would ask for a court hearing) that they saw you behind the wheel (and, likely now, you'd also be on bodycam). That would likely be enough evidence - which is why you probably don't want to go to court, because the judge would be annoyed at you for wasting everybody's time, and you'd probably get more severe punishment.

That said, I did at times get smaller fine and less severe consequences from a speeding ticket by just pretending I am going to go to court (I didn't really want to, I wanted smaller fine :) - because policemen do not like to waste time in court either - so they would agree, that if I do not try to deny I did it, and do not force thus them to go to court and testify, they would agree to less severe violation (while still costing me $$, just not as much as it could). That's totally a thing, at least in the US. The risk, of course, if you are an ass about it and piss off the police officer, they'd say to heck with it, I'll go to court, and you'd have to go to court too, and as per above, you'd get punished more severely. So, always be polite, and it will be to your benefit.

As for automated speeding tickets, I'm not a huge fan of it. Too many cases of this system being wrong or abusive.