Over on slashdot.com, there is an article on a new device that will use GPS to monitor your speed. It will first warn you then even slow down your vehicle if you continue to speed. Britain and Australia are now set to test these out. In Britain at least they want to try them on taxis and buses first, something I don't think many in London would object to. I do not believe this will be implemented in every vehicle in the UK however.
The technology to do this has been around for quite a while. A lot of commercial vehicles have speed limiters that essential do this already, there are also a lot of vehicles that come from the factory with a top speed limit programmed in. Many of you are also now mentally listing a lot of reasons why this will not work in the long run: not able to respond to emergencies, false data creating the wrong speed limit, creating traffic problems from a software bug, and all of the resulting court cases from all of these. I also do not feel like I need to discuss the fact that we are not condoning aggressive driving or speeding so much as being controlled by some arbitrary device. That is another topic for another time. The simple fact it, this will create more problems than it would ever solve.
The reason I think you will not see wide spread adoption of this in the US. Money. Many city and county governments use traffic fines as a major source of income. You will notice I did not say law enforcement officers there. While that is true some of the time, it is a lot more complicated than that. Many municipal governments view drivers as a way to make money not just the local police. Truth is, many law enforcement officers hate traffic stops and would rather do something else. This is also related to the shortening of yellow lights as soon as a red light camera is installed.