NHTSA Launches Investigation Into Amazon’s Self-Driving Zoox Division

The National Highway Traffic Safety Administration (NHTSA) is looking into the Amazon-owned Zoox after two of its robotaxis were involved in crashes. The vehicles in question were effectively faulted with brake checking motorcycles. The autonomous cabs reportedly stopped abruptly and were rear-ended by the bikes.

According to Reuters, a preliminary evaluation was launched on Monday and encompasses roughly 500 vehicles equipped with the same Zoox Automated Driving System that was equipped to the Toyota Highlanders involved in the crash. Details about the crash are limited beyond it being a braking incident where the riders received minor injuries after colliding with the rear of the robotaxis.

From Reuters:

In March, Zoox said it was expanding its vehicle testing in California and Nevada to include a wider area, higher speeds and nighttime driving, as it competes with Alphabet's Waymo robotaxis. Amazon acquired Zoox in 2020 for $1.3 billion.

NHTSA said both crashes occurred during daytime lighting conditions and within the operational design limits of the Zoox system. NHTSA said its initial investigation confirmed "each of the Zoox vehicles was operating with the ADS engaged in the moments leading up to each collision."

The investigation will evaluate the Zoox Automated Driving System performance particularly relating to the collisions as well as "the behavior in crosswalks around vulnerable road users, and in other similar rear-end collision scenarios."

Automated test vehicles have had trouble with this for a while. One of the first complaints leveled at Waymo vehicles was that they would stop abruptly when confused. Similar criticisms were leveled at Cruise AVs before other roadway incidents became higher profile. But one does wonder what exactly was going on in the Zoox instances, as the person who strikes the rear of another vehicle is typically the one held accountable in most legal cases. The logic here is that they could have increased their following distance and should always be prepared to stop in the event of an emergency.

While that doesn’t assume any guilt on the part of the bikers, one does wonder exactly what they were doing in the moments leading up to the crash.

As someone who has a lot of seat time on motorcycles, your author knows that the braking advantage between automobiles and motorcycles can vary wildly. One would think that a bike would be quicker to stop thanks to having far-less mass to cope with and often playing host to stickier tires and larger brakes in relation to its overall size. But cars have a much larger contact patch with the pavement thanks to boasting more wheels. This helps trump the additional inertia automobiles need to overcome to stop. In many cases, a high-performance automobile will have superior braking performance at the limit. But the average motorcycle tends to be at least as good at stopping as most mainstream automobiles, with performance bikes often needing less distance overall to come to a halt.

The real advantage for four-wheeled vehicles comes by way of the operator having less to do during a hard stop. Drivers need only to apply the brake (and the clutch pedal if they’re using a manual transmission) when they need to halt in a hurry. By contrast, a motorcycle rider needs to modulate the front and rear brakes independently using both their right foot and hand in a manner that wouldn’t unsettle the bike while also applying the clutch with their left hand. Riders actually have to carefully balance what their entire body is doing to ensure good contact with the road in order to maximize braking performance.

For an experienced rider, this can be done on instinct. But newer riders, and even experts with less time on a specific bike, won’t have worked out the magic formula to get the most out of their brakes — thereby creating longer braking distances than the motorcycle is mechanically capable of achieving. This is actually one of the first things a reputable motorcycle safety course will teach riders, adding that they should always leave themselves an exit vector as a last resort.

That’s a long-winded way of suggesting that the Zoox-equipped Highlanders might not be the only ones that mucked up here. But we won’t know until more details of the incident are made public.

At any rate, this isn’t the first time Zoox has been under the regulatory microscope. In 2023, the NHTSA also opened an investigation into the self-certification process used by the company in 2022. The concern was that the company was fielding vehicles without traditional driving controls and that technically violated Federal Motor Vehicle Safety Standards (FMVSS). That probe is currently pending as the NHTSA attempts to verify if Zoox’s "certification basis depended upon unilaterally developed test procedures or determinations that certain standards were inapplicable due to the unique configuration of the vehicle."

Frankly, everything about autonomous test mules (and even some of the new driving aids that are becoming standard equipment) seems like a legal nightmare. Legislators and even some government regulators seem to have little understanding of how these systems function, let alone the vast differences between the functionality of what’s on offer from various companies.

[Image: Sundry Photography/Shutterstock]

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