Waymo's Level 4 Automation: What It Takes to Reach Level 5

Waymo's published safety research describes its automated driving system, the Waymo Driver, as SAE Level 4. Under the six-level framework established by SAE and referenced by the National Highway Traffic Safety Administration (NHTSA), Level 4 systems can handle the entire driving task without human input within a defined set of conditions and locations. Level 5 removes those boundaries entirely.

At Level 4, occupants are passengers rather than backup drivers once the system is operating within its intended conditions. Waymo can therefore describe its service as fully autonomous without claiming Level 5, because its cars still have defined operating limits.

Those limits are known as the operational design domain (ODD), which specifies where and under what conditions a self-driving system is designed to operate, including geography, road types, and weather. Level 5, according to NHTSA, would mean operating universally rather than within limited service areas.

Expanding a Level 4 system gives developers clear boundaries to work within. Waymo says its sixth-generation Driver has expanded capabilities for more diverse environments, including extreme winter weather, but as long as it still operates within defined boundaries, it remains Level 4.

Reaching Level 5 is much harder because removing boundaries dramatically increases what must be accounted for. Waymo's 2026 research on collision-avoidance testing noted that evaluating a Level 4 system is complicated by the potentially enormous number of operational scenarios. In May 2026, Waymos encountered flooded roads in Atlanta and San Antonio, leading the company to suspend or restrict some operations while it worked on improvements.

There is no reliable countdown to Level 5. NHTSA currently says Level 5 technology is not available in vehicles for consumer purchase, and the SAE levels describe capabilities rather than a development roadmap.