See https://waymo.com/safety/impact/#methodology https://waymo.com/safety/impact/#methodology They compile human crash data from various sources (NHTSA, state

See https://waymo.com/safety/impact/#methodology https://waymo.com/safety/impact/#methodology They compile human crash data from various sources (NHTSA, state data). But they are at a city level, not specific streets or areas. So they adjust the human benchmarks to be more representative of the areas where Waymo operates.