Brian Heaton, Government Technology Magazine, Dec 2013, says San Antonio, Texas, drivers with warrants for overdue traffic tickets don't have to go to court if stopped--they can get in the city marshal's car and talk to a judge via videoconferencing.
The software synchs with the license plate readers and an electronic court system. When the driver and judge decide on what is owed, the driver pays with a credit card--all in the squad car.
It's cleaner, insist the marshals--and usually the driver just forgot about the tickets.
It also saves time--an arrest can take hours of cop time.
San Antonio also has kiosks in grocery stores where people can pay tickets.
An effort is made to see if the driver matches the person ticketed. Then the car is pulled over. If the driver did not get the ticket, he or she is asked to tell the person who did it to take care of the situation.
If the person wants to contest the ticket, a trip to court is probably the next step.
I dunno--it seems to me pulling people over for unpaid tickets could be dangerous--what if the driver thought the marshal wanted something else and decided to fight or flee?