if they think they had their hands full trying to enforce a 55MPH speed limit...
Oh, they'ed bring that back with a vengeance, along with all other speed limits.
The GPS technology to do this will also monitor vehicle speed and you would receive automatic citations for exceeding any speed limit.
Likely they would require a cash bank account linked to the GPS and fees and fines would be deducted as you drive. Hit zero and it disables your car till you deposit more money.