Schematic representation of the projected error budget for H₀ with only Population II distance indicators, using the conservative estimates described in the text, where the current budget is given in black text and the projected budget after Gaia is in red text. Two paths are given; the first is the one described in the text that uses RR Lyrae to calibrate the TRGB and the TRGB to calibrate the SNe Ia (top fork), and the second is a path that calibrates the TRGB directly and then uses the TRGB to calibrate the SNe Ia (bottom fork). The scale bar at the bottom of the figure gives the approximate line-of-sight distance scale in units of Mpc for the measurements taken at each step of the Population II distance ladder. (Top fork) Illustration of the current CCHP distance ladder using the 5 trigonometric parallaxes with HST+FGS,  resulting in a 2.9% measure of H₀ (Section 7.1). Projected CCHP distance ladder error budget using ∼55 trigonometric parallaxes from Gaia, resulting in a 2.4% measure of H₀ (Section 7.2). (Bottom fork) Projected CCHP distance ladder bypassing the RR Lyrae and using the Hipparcos parallaxes for local TRGB stars, resulting in a 6.3% measure of H₀ (Section 7.3). Projected CCHP distance ladder using only the TRGB stars, but with improved Gaia parallaxes, resulting in a 2.3% measure of H₀ (Section 7.3). Despite minimizing the distance ladder and substantially reducing uncertainties, the number of SNe Ia zero-point calibrators sets the floor on the “local” measurement of H₀ at 2.1%.