HD map

A high-definition map (HD map) is a centimeter-scale, lane-level map used as prior knowledge in autonomous-vehicle perception and planning. Encodes lane geometry, traffic signs and signals, curbs, parking constraints, and other static features. The vehicle localizes against the HD map and uses it as scaffolding for perception and decision-making.

The distinction matters because HD-map vs map-less is a defining architectural choice. Waymo and most robotaxi services use HD maps as prior knowledge and accept the geofenced-deployment constraint that follows — maps must be built and maintained per operating area. Tesla FSD operates map-less, scaling instantly across geography but assuming perception is sufficient without prior knowledge. The two architectures imply very different scaling economics and very different failure modes.