How Self-Driving Cars Might Change Crash Testing Forever

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In a video posted on X, a Tesla enthusiast hops into what was once the driver’s seat of a new matte gold Cybercab. “Once” because the vehicle, which officially hit the streets earlier this month as part of Tesla’s Robotaxi ride-hail service, doesn’t have a steering wheel or brake pedals.

For the person in the front seat, this opens up new possibilities. Eat, game, watch, work. Or doze. To help you catch some z’s, the enthusiast demonstrates that the Cybercab’s seats can recline. “You can really go back,” he says. “You can really just sleep here.”

Or maybe don’t. In the official Cybercab rider guide, Tesla says passengers in its autonomous vehicles should keep their seat backs reclined no more than 35 degrees from vertical, with their seatbelts snug across their hips and their feet flat on the floor. Doing so “reduces the risk of injury in a collision or sudden stop.” (Tesla did not respond to WIRED’s questions for this story.)

Safety researchers say Tesla’s right here. In fact, passengers sitting in less-than-standard positions in any car are more likely to get hurt in a crash, even with their seatbelts fastened. According to US federal safety data, 42 people killed in traffic crashes in the past decade were identified as “seat back not in normal upright position, seat back reclined.”

That’s likely an undercount. After a crash, “it's really hard to identify people who are sitting out of position,” says Becky Mueller, a senior research engineer at the Insurance Institute for Highway Safety. Crashes move human bodies, and emergency responders work quickly to extricate hurt people from damaged vehicles. Very few are noting, or even have a way to note, exactly how victims were sitting before or during a crash.

Field data for reclined occupants is sparse, according to a spokesperson for the US National Highway Traffic Safety Administration, the federal vehicle safety regulator. But the emergence of self-driving cars like the Tesla Cybercab has nudged governments to take a fresh look at an older, dangerous issue.

“NHTSA decided to explore reclined occupants as a starting point for automated vehicle occupant safety based on the potential that occupants may choose to ride in a reclined posture if driving was no longer necessary,” the spokesperson wrote in a statement to WIRED.

A fresh look could take years. The vehicle safety standards automakers must meet today generally assume that vehicle occupants are seated upright, with their seatbelts across their hips. Airbags are configured for people sitting in this way, and the dummies used in crash tests have inflexible pelvises, which means they physically can’t slouch. To create new safety standards, studies must be proposed, funded, completed, and analyzed. Afterward, the government collects public comments from all comers.

“That’s the big excuse: ‘Oh, we can't revisit this regulation because it's such a hassle to open it back up, to go through the whole process,” Mueller says. Autonomous vehicles are finally convincing regulators “to open up some of these archaic rules and make modifications—maybe modifications that can help modernize regulations for other vehicles, too. It’s a good time to make sweeping changes.”

Crashing Out

Seatbelts are designed to be worn around upright, forward-facing bodies. So when a reclining body, or one sitting sideways, gets into a traffic crash, the seatbelt doesn’t do what it’s devised to—it tightens around the soft belly instead of the hard, bony pelvis.

It pushes hard, causing, perhaps, internal bleeding, lower spine and pelvis injuries, or damage to internal organs. Lower leg and foot damage are more common when seatbelts aren’t worn properly, and even if a passenger can recover, these are the sorts of injuries that can be most debilitating because they affect everyday mobility.

Today, companies hoping to deploy self-driving cars with different seating configurations mostly choose to go through what can be a lengthy process to get special government approval. Regulators seem to want to see that even before they’ve officially adjusted safety standards, autonomous-vehicle companies can prevent some of those worst injuries.

Zoox’s green, toaster-like vehicle is bidirectional, lacks a steering wheel, and features carriage seating, where passengers can sit face-to-face on opposing bench seats. Zoox, an Amazon subsidiary, tried in 2022 to self-certify that its vehicle met safety standards, but the federal government didn’t buy it. In the fall of 2025, the company officially applied for special approval. The process took months, and Zoox received permission this summer to use up to 5,000 cars in its robotaxi service for two years. (Tesla is also trying to self-certify its Cybercab; the NHTSA is currently investigating the issue.)

But the government is looking for a more permanent solution to driverless safety questions. In a March report to Congress, the NHTSA indicated its researchers are at least looking into how to stop the kind of injuries that occur in cars, and especially driverless ones, where passengers aren’t sitting exactly as the current standards anticipate they will. The agency “continues to refine its understanding of human response kinematics and injuries for various-sized occupants in forward- and rear-facing reclined seating conditions,” the report said.

One area of study: Advanced crash-test dummies designed to be tested with the sorts of seatbelts and seating conditions found in autonomous vehicles.

Big Dummy

Humanetics, the world’s largest manufacturer of crash dummies, is working on it. The dummies it and a small number of other global manufacturers make are called THOR, or Test device for Human Occupant Restraint. Crash tests with THORs are written into some countries' vehicle safety standards globally, and many consumer crash-testing programs use the devices in their tests.

Humanetics’ dummies come in different sizes, with models for varying ages and sexes. They’re far from the plasticky mannequins of old. These newer dummies cost hundreds of thousands of dollars, mimic the human body's responses, and are studded with sensors that measure their every movement. Since 2019, Humanetics has been testing THOR-AV, a new line of dummies and simulated online tools developed specifically to test the seating designs and postures seen in driverless cars. The THOR-AV has a more flexible pelvis than other THORs and can be adjusted to 25-, 45-, and 65-degree angles. The future, it seems, is in repose.

But right now, no regulators or outside safety groups require crash testing with the THOR-AV dummies, says Chris O'Connor, the president and CEO of Humanetics. He expects the first country to mandate the new crash-test products won’t be the US, but China, which has spent the past decade aggressively pushing its inexpensive and impressive electric vehicles into new global markets. “China is moving faster than anyone,” he says. “They want to be considered as a safety leader.”

CCARI, a Chinese certification body, has run hundreds of tests with the THOR-AV dummy, O’Connor says. He expects the country to require reclined crash tests in two or three years. European countries that sell into China would have to follow, and O’Connor says automakers there have started working with the new crash dummy to prepare.

China’s auto regulator also proposed new rules in June cracking down on so-called “zero-gravity seats,” a trendy design now found on tens of Chinese car models, where seats recline steeply to distribute body weight more evenly, making it easier for occupants to nap as they travel. The proposed rules would prevent the driver’s seat from reclining more than 35 degrees and would require risk warnings if a seat is reclined while a vehicle is traveling at high speeds.

“Unfortunately, the US has done very little,” O’Connor says. He worries that autonomous vehicles have actually set back safety standards, maybe by more than a decade. For years, tech developers and automakers promised that a technology that wouldn’t get drunk, high, or drowsy was right around the corner. Why would regulators adjust anything when perfect, robotic road safety was close at hand? But it hasn’t worked out that way, and the government is playing catch-up.

Alex Mueller, a senior research scientist at the Insurance Institute for Highway Safety who researches driver assistance and automation technologies, is watching the US’s process of revising its vehicle safety standards closely. (She’s not related to her IIHS colleague Becky Mueller.) The Trump administration is streamlining and updating rules to make it easier and faster for self-driving cars to hit public roads. Alex Mueller is a bit apprehensive.

“Modernization can’t be an excuse to remove core safety standards that are demonstrably important to public safety,” she says. Driverless cars may be safer in some ways. But tweak anything about the car safety system—remove a steering wheel, allow a person to face the other direction, recline seats to horizontal—and the whole enterprise should be reexamined. “We can’t throw the baby out with the bathwater,” she says.