  Using a nonlocal macroscopic LWR-type traffic flow model, we present an
approach to control the nonlocal velocity towards a given equilibrium velocity.
Therefore, we present a Lyapunov function measuring the $L^2$ distance between
these velocities. We compute the explicit rate at which the system tends
towards the stationary speed. The traffic is controlled by a leading vehicle.
Numerical examples demonstrate the theoretical results and possible extensions
of them.
