I'm happy with that response. The problem is how long would it take before all vehicles were of this type? What happens in the meantime when there is a mixture? I'm not sure I want to be in a driver less car with a mixture of vehicles on the road which are not talking to each other.Assuming all vehicles had a transponder fitted, self driving or not, then the self drive would know where and how fast any vehicles within range would be. It would not need to see them.