  We examine vortex flow states in periodic square pinning arrays with one row
and one column of pinning sites removed to create an easy flow crossed channel
geometry. When a drive is simultaneously applied along both major symmetry axes
of the pinning array such that vortices move in both channels, a series of
coherent flow states develop in the channel intersection at rational ratios of
the drive components in each symmetry direction when the vortices can cross the
intersection without local collisions. The coherent flow states are correlated
with a series of anomalies in the velocity force curves, and in some cases can
produce negative differential conductivity. The same general behavior could
also be realized in other systems including colloids, particle traffic in
microfluidic devices, or Wigner crystals in crossed one-dimensional channels.
