Face-on view of the median radial motions, V_R, for the young giant sample (left panel) and the Cepheids sample (right panel), compared to different spiral arm geometries from literature: Reid et al. (2019) (black solid lines, both panels), Poggio et al. (2021) (grey shaded contours, left panel) and Drimmel et al. (2024) (coloured lines, right panel). For the Drimmel et al. (2024) model, different colours indicate the Perseus arm (grey), Local/Orion arm (orange), Sagittarius-Carina arm (blue), and Scutum arm (red).