Results published in the paper "Dissipation of stop-and-go waves via control of autonomous vehicles" show that it is possible in principle to mitigate the propagation of traffic waves on a ringroad using a single autonomous vehicle. The proposed controller for the vehicle, called the Follower-Stopper, requires prior knowledge of the characteristic velocity of the ringroad in order to fully attenuate the oscillations in system. Here the characeteristic velocity of the vehicle refers to the velocity of each of the vehicles in the constant velocity solution that any traffic dynamical system admits as a solution. Of course in real-world situations one does not have complete knowledge of the state of the system, so determining the characteristic velocity poses a challenge. We propose a solution to this problem using plant inversion.