I try to do the same, and do my part to smooth out the wrinkles in traffic. What I would really like in a car is not only my current speed, but the relative sp

I try to do the same, and do my part to smooth out the wrinkles in traffic. What I would really like in a car is not only my current speed, but the relative speed to the car ahead of me. Given my car has cameras and other sensors for cruise control and other features this ought to already be possible.