A few weeks after a 76-year-old man a woman was killed when a Tesla, operating in fully autonomous driving, crashed into his Texas home, the National Transportation Safety Board concluded that the driver of the car had overridden the driver-assist mode and accelerated into the building.
Michael Butler, 44, was driving the Tesla Model 3 that killed Martha Avila on June 19. The vehicle was traveling 70 mph when the crash occurred, the agency said.
According to an NTSB report published Wednesday, the car was on a residential road when it “partially entered a driveway and crashed into a residence.”
The driver had activated Tesla’s advanced driver assistance system, fully autonomous driving (supervised) at the time of the accident, according to the NTSB report.
But, it continues, “electronic data retrieved from the vehicle indicated that prior to the crash, the driver manually overcame FSD (supervised) by depressing the accelerator pedal to 100%, and that the vehicle speed was greater than 70 mph when the crash occurred.” »
The driver of the car, Michael Butler, was charged this week with manslaughter in connection with Avila’s death.Courtesy of the Barbour familyAs a result, the woman inside the home was killed and the driver suffered minor injuries, the NTSB said.
Butler has since charged with manslaughter in connection with Avila’s death. Prosecutors and investigators have not yet said whether the car was involved.
An attorney for Butler did not immediately respond to a request for comment on the findings.
The agency noted that Rose Hollow Lane residential road is subject to a 30 mph speed limit. Additionally, at the time of the crash, “the weather was clear, the road was dry, and daylight conditions were present,” the NTSB report states.
The NTSB’s findings echo what Ashok Elluswamy, Tesla’s vice president of AI software, said days after the crash, defending the vehicle’s systems.
“In this case, the driver manually overrode autonomous driving by pressing the accelerator all the way to 100 percent of the accelerator pedal in this residential area,” Elluswamy said. written the on June 22.
Tesla and its CEO, Elon Musk, did not immediately respond to an emailed request for comment Thursday.
But Philip Koopman, a professor emeritus at Carnegie Mellon University who has worked on the safety of self-driving cars for 30 years, told NBC News that the NTSB report’s findings may not tell the whole story.
He said the NTSB must also determine whether “a computer or electronics malfunction caused a false reading of the accelerator pedal.”
“As with any allegation of unintended driver acceleration, a thorough investigation must take into account the potential for human driver error, but also mechanical failure, electronic failure and software failure,” he said.
According to the arrest affidavit, Butler told police he did not feel sick at the time of the crash and had no alcohol or drugs in his system.
He said he was making a DoorDash delivery when he changed the music on the Tesla’s touchscreen and ended up “blacking out,” according to court documents.
No further information was available on Butler’s condition at the time of the accident.
Koopman pointed out that the “100 percent pedal position” at the time of the crash could be due to a number of other factors, including the driver’s foot, but also a foreign object, mechanical pedal malfunction, wiring harness failure, computer hardware or software malfunction, among other factors or a combination of factors.
“To the extent that Tesla makes relevant information available, the NTSB should also look for potential common cause failures in otherwise redundant systems,” Koopman suggested.
He added that he hopes the NTSB’s final report “will clarify what potential causes other than human driver error cannot be ruled out due to lack of available information.”
Brett Schneider, who represented the families of two victims in another Tesla crash, said the driver’s behavior reported by the NTSB “is not ordinary … on a low-speed residential street.”
“Tesla has faced years of allegations from drivers who reported that their vehicle was suddenly accelerating without warning, only to be told that the recorded data blamed them,” Schreiber explained. “But electronic data loggers only record values generated by the vehicle’s computer.”
The NTSB said the crash remains under investigation pending a determination of the probable cause. The National Highway Traffic Safety Administration also opened a special investigation into the crash.
NBC News previously reported that people involved in other similar Tesla accidents – some of which resulted in deaths – have taken issue with the way the Musk-led company advertises fully autonomous driving, noting that the technology requires more human oversight than its name suggests.
“The more automation of driving tasks involves, the more important it becomes to support the driver’s attention, understanding and ability to intervene when the system reaches its limits,” Bryan Reimer, an MIT researcher and advisor on the future of mobility and AI, said Thursday after reviewing the NTSB report.
He added: “Names such as Full Self-Driving can communicate a level of capability that the system does not actually provide. Clearer naming is a fundamental part of helping drivers understand their ongoing responsibility.”