Galactic kinematics for distance determination. Left: contours mark lines of constant projected v_LSR based on the (flat) rotation curve of model A5 from Reid et al. (2014). Regions for which kinematic distances are not computed (kinematic avoidance zones) are shown in gray with dashed borders. The Sun (sun symbol) and Galactic center (star) are marked for reference. Cyan contours mark d_☉ in 5 kpc intervals, and the red circle identifies R_gal = 4 kpc, inside which the Galactic bar dominates the kinematics. Right: the magnitude of the derivative of v_LSR with respect to d_☉ across the Galactic plane (grayscale). Magenta hashing identifies regions where |dv_LSR/d(d_☉)| ⩽ 5 km s⁻¹ kpc⁻¹ (i.e., a projected peculiar motion of 5 km s⁻¹ will yield a ⩾1 kpc distance error). Kinematic avoidance zones are marked by gray hashing, and yellow contours mark constant values of |dv_LSR/d(d_☉)|.