From The Telegraph:
Drivers could have their speed controlled by satellite to stop them from breaking the limit following a Government trial of new technology. Cars fitted with the system would have their speed automatically monitored by satellites, which would also be programmed with the speed limits for different roads.
I don’t think it’ll fly. There’s no true money to be made in preventing a crime from happening, unless you have some sort of “pre-crime” system. I think the technology described would be more likely used to track violations as they happen and cite the drivers, not to mention the easy tie-in with toll roads.
Oh, and just like Columbus brought over rats and pidgeons, don’t be too surprised to see this system skipping across the pond to a state near you.