  We study numerically the motion of vortices in dirty type II superconductors.
In two dimensions at strong driving currents, vortices form highly correlated
``static channels''. The static structure factor exhibits convincing scaling
behaviour, demonstrating quasi long range translational order in the transverse
direction. However order in the longitudinal direction is only short range. We
clearly establish the existence of a finite transverse critical current,
suggesting strong barriers against small transverse driving forces. These
results are most consistently interpreted in terms of the recently proposed
moving glass picture, modified to account for the strong anisotropy.
