Common Sense Becomes Critical Missing Link for Autonomous Vehicles

July 17, 2025 – Waymo has proven that autonomous vehicles can operate safely at scale, completing hundreds of thousands of rides weekly with its fleet of roughly 4,000 cars. The company’s analysis of 220 million fully autonomous miles shows a 94% reduction in serious or fatal crashes compared to human drivers. Yet two separate recalls in 2026—one for driving into flooded roads, another for entering closed construction zones—reveal a persistent gap: these vehicles lack common sense.

The industry is now recognizing that perception, prediction, and planning are no longer the primary bottlenecks. The real challenge is instilling machines with the judgment of an experienced driver. A human instinctively knows that standing water might hide a washed-out road, that a construction barrier means “do not enter,” and that temporary signs override permanent lane markings. Autonomous systems, however, can still fail when faced with such contextual nuances.

Current safety metrics—disengagements, collision rates, intervention frequency—are retrospective. They only flag failures after they happen. The missing piece is a proactive evaluation of common sense. How does the vehicle anticipate a child near the curb? Does it infer that a parked truck may conceal pedestrians? Can it reason that an unusual obstacle should be treated with caution, even if never seen before?

New Metrics on the Horizon

On July 16, 2025, the National Highway Traffic Safety Administration (NHTSA) announced a new initiative to develop common-sense reasoning benchmarks for autonomous driving systems. In collaboration with research institutions including MIT and Stanford, the agency aims to create a continuous evaluation framework that tests a vehicle’s contextual understanding during routine operation, not just after incidents. This marks a shift from outcome-based metrics to understanding-based ones.

“The industry has mastered perception, but perception is not understanding,” said Dr. Elena Voss, a leading AI safety researcher at Stanford. “A car can identify a barrier perfectly, but if it doesn’t understand that the barrier means ‘stop’ in this specific context, the system is still dangerous.”

Why Common Sense Is So Hard

Common sense is not a single skill but a bundle of capabilities: applying prior knowledge, reading intent, inferring causality, and adapting to novel situations. While large language models and foundation models have shown promise in scripted reasoning, real-world driving requires split-second decisions with incomplete information. The 2026 Waymo recalls illustrate the gap: the vehicles had the technical capability to detect flooding and construction zones, but lacked the higher-level reasoning to override standard driving rules.

“Autonomous driving has reached a plateau where incremental improvements in sensors or models yield diminishing returns,” said Igal Raichelgauz, Founder and CEO of Autobrains, in a recent analysis. “The remaining frontier is intelligence—the ability to apply knowledge, interpret context, and reason about situations never encountered before. That capability is common sense.”

Industry Response and Future Directions

Several companies are already exploring approaches. Waymo has incorporated additional simulation-based training for uncommon scenarios, while competitors like Cruise and Zoox are investing in situational reasoning modules. The new NHTSA initiative is expected to produce a draft set of common-sense evaluation criteria by early 2026, which could influence regulatory approvals and insurance ratings.

“We need to measure not just whether a car avoids a crash, but whether it would have avoided a crash had it shown better judgment,” said NHTSA Deputy Administrator Michael Thornton. “That means observing thousands of routine decisions where no incident occurs—like slowing down when a pedestrian looks at their phone near the curb.”

The shift challenges the entire autonomous driving community. For years, the mantra has been “more data, more compute.” Now, the focus is turning to “more understanding.” As vehicles are deployed in more complex environments—narrow streets, construction zones, unpredictable pedestrian behavior—the need for common sense becomes existential.

Conclusion: From Outcome to Understanding

The history of autonomous driving has been a series of breakthroughs: teaching machines to perceive, predict, and plan. But the next leap will require teaching them to reason. Until autonomous vehicles possess common sense, they will continue to surprise us in ways that humans do not. The NHTSA’s move to create common-sense benchmarks is a critical step toward making self-driving cars not just safe, but truly intelligent.

Igal Raichelgauz is the Founder and CEO of Autobrains. This article incorporates his analysis alongside recent regulatory developments. All events and statements are based on public information available as of July 17, 2025.