If Waymo Cars Are Level 4 Automation, What Does It Take To Be A Level 5?

Seeing a automobile transfer by metropolis visitors with nobody within the driver’s seat could make it really feel like Waymo has already reached the very best attainable stage of automation. From a passenger’s perspective, there isn’t any steering, no monitoring and no want for a human to intervene. The automobile handles the complete journey by itself.

However underneath SAE’s (Society of Automotive Engineers) driving automation framework, that functionality continues to be Stage 4 fairly than the very best: Stage 5. The important thing distinction is not how “impartial” the driving seems to be in observe, however the place that independence is allowed to exist. At Stage 4, the system can totally deal with the driving activity with out human enter — inside an outlined set of circumstances and places. Stage 5 removes these boundaries solely.

Strictly talking, it is the Waymo Driver, the corporate’s automated driving system, that is labeled as Stage 4. Waymo’s published safety research describes it as an SAE Stage 4 automated driving system, and that classification explains why an empty driver’s seat would not mechanically make a Waymo Stage 5.

There are a complete of six SAE automation ranges, numbered 0 by 5. The National Highway Traffic Safety Administration (NHTSA) begins its breakdown at Stage 0, the place the human does all of the driving even when security methods can briefly intervene. Stage 1 can constantly help with steering or acceleration and braking, whereas Stage 2 can deal with each on the identical time. In every case, the motive force stays answerable for the automobile.

Stage 3 adjustments who’s doing the driving. The system can deal with the complete driving activity underneath sure circumstances, however the human have to be accessible to take over when requested. At Stage 4, that requirement disappears. As soon as the automated system is working inside its meant circumstances, the occupants are passengers fairly than backup drivers.

That is additionally why Waymo can describe its service as totally autonomous with out claiming SAE Stage 5. Its vehicles can full rides with out anybody sitting behind the wheel, however that skill nonetheless has outlined working limits.

These limits are normally described as an operational design area, or ODD. In easy phrases, the ODD defines the place and underneath what circumstances a self-driving system is designed to function. That may embrace geography, the forms of roads it is designed for and the climate circumstances it could possibly deal with. SAE defines it because the set of circumstances an automatic driving system is designed for, and Stage 4 methods are anticipated to handle driving on their own within those boundaries.

At Stage 4, the system handles the complete driving activity inside its ODD. Stage 5 removes that limitation: NHTSA describes it as working universally fairly than inside restricted service areas. So Stage 5 is not a couple of automobile being “extra autonomous” throughout a selected maneuver. A Stage 4 Waymo already handles steering, braking and decision-making by itself when working inside its area. The distinction is scope, not who’s answerable for driving.

That is why Waymo can preserve bettering its system and nonetheless stay Stage 4. For instance, Waymo says its sixth-generation Driver has expanded capabilities for more diverse environments, together with excessive winter climate. Increasing into new cities or climate varieties makes the system extra succesful, however so long as it nonetheless operates inside outlined boundaries, it stays Stage 4 fairly than Stage 5.

Increasing a Stage 4 system provides builders boundaries round the issue. They will outline the place the system ought to function, determine the circumstances it must deal with and check its conduct towards situations related to that area. Eradicating these boundaries dramatically will increase what needs to be accounted for.

That is already troublesome at Stage 4. In its 2026 analysis on collision-avoidance testing, Waymo famous that evaluating a Stage 4 system is difficult by the potentially enormous number of operational scenarios by which a hazardous scenario would possibly develop. Its methodology identifies doubtlessly hazardous situations utilizing human driving knowledge, knowledge from Waymo’s automated-driving checks and skilled data.

Climate provides a concrete instance of these limits. In Might 2026, Waymos encountered flooded roads in Atlanta and San Antonio, main the corporate to droop or limit some operations whereas it labored on enhancements.

There is not a dependable countdown to when Stage 5 will arrive. NHTSA presently says Stage 5 know-how is not accessible in automobiles for shopper buy, and the SAE ranges describe capabilities fairly than a improvement roadmap.