Mean −⟨u⟩ velocity (see colour bar) predicted by the analytical model in the (R, v) space, for stars aligned with the Sun and the Galactic centre (i.e. at the solar azimuth). The bins are ΔR = 0.4 kpc and Δv = 5 km s⁻¹. The coloured lines correspond to the positions in this space of the OLR (red), 3:1 (pink), 4:1 (blue), 6:1 (purple), and CR (green). The velocity −⟨u⟩ was chosen to facilitate the qualitative visual comparison with the figures in Laporte et al. (2019) and Fragkoudi et al. (2019).