  We introduce a combined fully three-dimensional macroscopic/microscopic
transport approach employing relativistic 3D-hydrodynamics for the early,
dense, deconfined stage of the reaction and a microscopic non-equilibrium model
for the later hadronic stage where the equilibrium assumptions are not valid
anymore. Within this approach we study the dynamics of hot, bulk QCD matter,
which is being created in ultra-relativistic heavy ion collisions at RHIC. Our
approach is capable of self-consistently calculating the freezeout of the
hadronic system, while accounting for the collective flow on the hadronization
hypersurface generated by the QGP expansion. In particular, we perform a
detailed analysis of the reaction dynamics, hadronic freezeout, and transverse
flow.
