  We present simulation results of the moving Bragg glass regime of a driven
two-dimensional vortex system in the presence of a smoothly varying weak
pinning potential. We study the critical transverse force and (i) demonstrate
that it can be an order of magnitude larger than previous estimates (ii) show
that it is still observable when the system is driven along low higher-order
lattice vectors. We confirm theoretical predictions that the critical
transverse force is the order parameter of the so-called moving glass phase,
and provide data to support experimentalists verifying the existence of a
critical transverse force.
