Driverless cars are becoming jerks — and they’re safer because of it

July 29, 2025 Yanac

AI-powered AVs are increasingly honking, taking sharper turns, rolling through stop signs, or edging into crosswalks — mimicking human behavior that ironically could make them safer vehicles.

The vehicles use AI to observe and shadow human behavior as they traverse millions of miles of roadways. Tesla’s Shadow Mode, for example, quietly monitors human driving, comparing it to the system’s own choices to improve autonomous performance over time, according to Jonathan Davenport, a Gartner senior director analyst.

“However, this also raises an important question: should AVs mimic all human behavior?” he said. “While some human adaptations are beneficial, such as knowing when to be assertive in traffic, others — like speeding or rolling stops — are illegal. Striking the right balance is key, because we need to teach vehicles to drive like the best versions of ourselves— not the average ones.

University of San Francisco engineering professor William Riggs, who has been studying Waymo advances as he rides in AVs multiple times a week, recently told a San Francisco Chronicle reporter that he’s noticed a shift. Waymo’s Jaguar SUVs now drive more naturally and confidently, adapting to San Francisco’s chaotic traffic.

They’re even assertive enough to honk when cut off.

Mountain View, CA-based Waymo has more than 1,500 vehicles in its robotaxi fleet across five metropolitan areas. Its autonomous tech, Waymo Driver, is powered by AI, enabling it to learn from more than 100 million real-world miles and billions of simulated ones, according to the company. AI helps Waymo Driver understand its surroundings, predict others’ behavior, and navigate safely across varied driving conditions.

“Our Driver uses the horn in situations where human drivers would find it appropriate and helpful,” said David Margines, director of product management at Waymo.

The company shared a video of its vehicle in San Francisco automatically honking and reversing to let a garbage truck back up — then safely continuing on its route. “The Waymo Driver is designed to combine the best of human driving intuition with advanced technical capabilities that exceed human limitations,” Margines said. “Our goal is to create a driving experience that safely and effectively integrates with existing traffic patterns and norms.”

AVs are beginning to mimic human behavior in three major ways, according to Davenport. They’re becoming more assertive (Tesla’s Shadow Mode mimics human driving); adaptive (Mobileye’s RSS software adds human-like safety judgment); and communicative (Mercedes’ turquoise lights signal when its in autonomous mode, replacing eye contact and gestures).

“As autonomous technology grows, clear communication will be essential — not just between vehicles, but with all road users,” Davenport said.

For its part, Waymo said a “more confident and assertive” Waymo Driver is a safer vehicle. The company has several features to that end:

At four-way stops, vehicles now “more confidently” take their turn when it’s appropriate, similar to how experienced human drivers do.

When merging into traffic, Waymo Driver can better predict other drivers’ intentions and smoothly join the flow.

Around obstacles, such as double-parked vehicles, Driver can navigate more efficiently while maintaining safe distances.

“These improvements come from understanding local driving customs and norms while maintaining our safety standards,” Margines said.

Where Shared Autonomous Vehicles (SAVs) fleets are now operating.
University of Texas at Austin/Kara Kockelman

Waymo’s own data — drawn from more than 25 million fully driverless miles — along with a Swiss Re insurance study, shows its driverless vehicles get into fewer serious crashes than human drivers, regardless of who’s at fault.

“Interestingly, assertiveness and safety are often seen as opposing things that need to be balanced,” Margines said. “But what we’re finding is quite the opposite: assertiveness and safety actually go hand in hand — and the safest behavior is often assertive.”

For example, when merging onto a highway or changing lanes in dense traffic, being too hesitant can be just as problematic as being too aggressive, he said.

AVs that use noises, lights — and even some day display LED messages on the vehicle — can improve safety by increasing communication. Some AVs are already talking.

That’s the case with robotaxis from Foster City, CA-based Zoox; it designs purpose-built, all-electric robotaxis (no steering wheel or pedals) optimized for riders rather than drivers. Unlike Waymo’s vehicles, Zoox robotaxis don’t honk like humans — or even like some other AVs. Instead, they use a 30‑channel directional speaker array to direct targeted audio at pedestrians or others, offering what Zoox considers a less disruptive form of communication. (Zoox is owned by Amazon.)

“I was here on campus one day when somebody who had just gotten out of a Waymo didn’t close the door fully,” said Kara Kockelman, a transportation-engineering professor at the University of Texas at Austin who studies shared and autonomous vehicle systems. “So the car was asking a passerby to ‘please shut my door.’ So somebody eventually did, and that allowed it to go on its way. And so with pedestrians, it might just simply talk at them.”

There may even come a time when a passenger can tell the robotaxi the kind of ride they want: to go faster, go slower or even with whom they want to ride. “I assume that they will allow that kind of specification, like some people will be allowed to ride only with other female passengers, or only with other UT students, let’s say, for shared rides,” she said.

Kockelman’s own experience as a passenger in an AV was “super boring.”

“I did feel a little uncomfortable because it was quite assertive. So, if the pedestrian, or the scooter, or the bicyclist we were approaching or trying to pass changed directions or dropped something, it would have been a potentially dangerous situation.”

That said, Kockelman made no bones about it: AVs are naturally better drivers than humans — resulting in about 90% fewer crashes per mile driven versus the average human driver. “Maybe the best human drivers could rival them, but I don’t think others will be able to,” she said. “I think Waymo is probably beating our estimates. But of course, they are driving quite cautiously still.”

She noted that robotaxis such as Waymo’s have generally stuck to local roadways and avoided highway driving out of an abundance of caution; how well they drive could change in the future as speed and congestion become factors.

One major reason AVs can drive more safely than humans is they’re aware of more of their environment — in other words, they know what’s around them at all times, even if it can’t be seen with the naked eye. “On the road, they know where every curve is,” she said. “They memorize everything, and they have eyes on every corner of the vehicle and on the top of the vehicle. So they’re seeing all sorts of things that you and I absolutely cannot see.”

Honking may seem obnoxious, but Kockelman notes it’s a useful safety tool that communicates when others make mistakes.

Then there are those other times.

“When you’re waiting at a red light, and it turns green and the person in front of you has no idea that it’s turned green because they’re not paying attention, you need to communicate with those drivers,” she said. “If somebody doesn’t see me, I want them to hear me.”