I don't understand the importance of using sound to control the lights in your request. It would be very difficult to get the correct direction the police car is traveling, distance from the intersection, ect... from the siren. The government isn't likely to replace the existing system, unless yours is greatly superior to what's already in use. And finally, in my mind I see more ways to abuse such a circuit, than it being a benefit. It's your project though, and perhaps you invision aspects of this project that I am unable to realize, but I'm pretty sure that this isn't very productive, but who really knows. Our government wastes millions of dollars, almost daily...