The only people who can force you to pay those automated tickets are the courts and they 100% have to prove who was driving the vehicle. Or, you can voluntarily pay, I suppose...
One of my old neighbors got a letter (complete with a picture of the "perp") kindly asking him who was driving his car and I told him to just ignore it unless they drag him into court since they obviously knew he wasn't driving. There's also the "spousal privilege" thing, his wife was driving, so they theoretically couldn't even force him to say who the offender was.
It probably depends on the state; in many states you can't get out of a parking ticket by saying you weren't the person driving and there's no reason to not use the same process for speeding and red-light cameras. Of course that requires changing the laws, and some states did not do so.
One of my old neighbors got a letter (complete with a picture of the "perp") kindly asking him who was driving his car and I told him to just ignore it unless they drag him into court since they obviously knew he wasn't driving. There's also the "spousal privilege" thing, his wife was driving, so they theoretically couldn't even force him to say who the offender was.