Radial velocity of the disc without α transition (top) and with α transition (bottom). The black and white lines mark the transitions in the α viscosity parameter as defined by Eq. (3) and as shown in Fig. 1. In the bottom panel, the parts of the disc above the red line are fully active with α_A. They are overplotted in the top plot as well to show where these transitions would be. The grey line represents the pressure scale-height H. Positive velocities mark an outward motion, while negative velocities indicate an inward motion.