I would ignore this. No doubt about it.
They cant do fuck.
EDIT: If you were driving a rental car, they might have your credit card on file and take it from you that way. As for legal ramifications here, I wouldnt worry about it at all.
I just reported the credit card I used for the rental as lost/stolen. They aren't getting me
that way. However, when I brought the subject up in another forum, I got this reply...
Unpaid fines accumulate extra charges, and whilst they might ignore following up a small amount (as it is now), most state authorities employ debt chasers to collect, and once the unpaid on times fees start adding it might be worthwhile someone chasing you for the debt.
if paid I doubt it will be notified to your home country licence authority.
Unpaid, it is quite possible it will be noted if you return to Australia in future.......was the vehicle you were driving that of a friend - if so pay it or the authorities may disbelieve the car owner wasn't in fact driving themselves. and thus harass the friend/owner.
If it was a rental vehicle, you probably find the rental company billing your credit card for their time and effort providing your details to the authorities.
While I doubt a debt collector is going to fly all the way from Australia to DC to collect money from me
(Though that WOULD be hilarious), I sure hope they don't have debt collectors working here in the states. It would be ironic if they hired
Sakal CAI to do it. Jason Osbourne after me would be a scream, though I doubt it'll happen.