Automatic speed control system in Delhi

Today while coming back from the office we discussing about a device that can be factory fitted in all the cars and that device would keep track of overspeeding.

What would this system do?

1. If the car overspeeds then ticket should be sent to the registered address and there could be a relaxation limit of +-5 Kms/hour or rather before sending the ticket system should check the number of previous overspeeding attempts. There should be some mechanism where car speed is sent to the server every Kilometer.
2. That device should be GPS enable so that location can also be tracked.
3. Different places have different speed limit hence this information can be either downloaded to the car itself or the speed of the car is sent to the central server.
4. Now speed limits should be different in the day time and mid night. All this information can be fed in the system.
5. If we take this further, in true sense speed limits should be based on the amount of traffic moving on the road, hence the system should be able to figure out the number of cars moving on the road and adjust the speed limits. We can call this flexi limits where one need not worry about the limit, the driver should not worry as long as he is driving safe i.e. if there are less cars on the road that implies that there is a scope of extra speed and vice versa.

Unanswered questions
1. How do we identify the Road Lanes? Each lane has different speed limit.
2. Fitting a device in Car is not tough but how to setup the infrastructure across the city? What technology can be used to implement this system. I think some existing infrastructure can be used to implement this, like GMS/CDMA mobile networks can be used.

I wish to study this topic further and make a model. Please add your points or something that I might have missed.