Optimal motorway traffic control strategies are derived on the basis of a highly accurate, non-linear, discrete dynamical traffic flow model. By application of these strategies, traffic can be driven back to its nominal state condition in a prescribed optimal manner after occurrence of a severe disturbance. Because of the high order of the optimal traffic control problem, four known decomposition methods arc applied, in order to reduce the computational effort needed for its solution. Simulation results obtained for a realistic traffic situation on a 30 km long motorway are discussed both from an algorithmical and a traffic control engineering viewpoint.