Minimum tunneling time in quantum motion

Starting out with the dwell time approach by Smith for stationary one-dimen sional tunneling problems, we introduce the notion of the minimum tunneling time required for traversal through an arbitrary potential barrier. The ne wly devised time scale is based on a simple variational principle and prese nts a strictly local quantity not depending on the asymptotics of the poten tial distribution. Its properties are illustrated using the customary squar e barrier as an example. The minimum tunneling time approach cannot support the existence of superluminal velocities in barrier penetration.