Teslas with partially automated driving systems are a step closer to being recalled after the United States elevated its investigation into a series of collisions with parked emergency vehicles or trucks with warning signs.
The National Highway Traffic Safety Administration (NHTSA) said on Thursday it was upgrading the Tesla probe to an engineering analysis — another sign of increased scrutiny of the electric vehicle maker and automated systems that perform at least some driving tasks.
Documents posted on Thursday by the US agency raise some serious issues about Tesla's Autopilot system.
The agency found it was being used in areas where its capabilities were limited, and many drivers were not taking action to avoid crashes despite warnings from the vehicle.
The probe now covers 830,000 vehicles, almost everything that the Austin, Texas, car maker has sold in the US since the start of the 2014 model year.
The NHTSA reported that it had found 16 crashes into emergency vehicles and trucks with warning signs, causing 15 injuries and one death.
Investigators will evaluate additional data, vehicle performance and "explore the degree to which Autopilot and associated Tesla systems may exacerbate human factors or behavioural safety risks, undermining the effectiveness of the driver's supervision," the agency said.
A request for comment has been sent to Telsa.
An engineering analysis is the final stage of an investigation, and in most cases the NHTSA decides within a year if there should be a recall or the probe should be closed.
In the majority of the 16 crashes, the Teslas issued collision alerts to the drivers just before impact.
Automatic emergency braking intervened to at least slow the cars in about half the cases.
On average, Autopilot gave up control of the Teslas less than a second before the crash, the NHTSA said in documents detailing the probe.
The NHTSA also said it was looking into crashes involving similar patterns that did not include emergency vehicles or trucks with warning signs.
The agency found that in many cases, drivers had their hands on the steering wheel as Tesla required, yet failed to take action to avoid a crash. This suggests that drivers are complying with Tesla's monitoring system, but it does not make sure they are paying attention.
In crashes where video was available, the drivers should have seen the first-responder vehicles an average of eight seconds before the impact, the agency wrote.
The agency will have to decide if there is a safety defect with Autopilot before pursuing a recall.
Effectiveness of driver-monitoring system questioned
Investigators also wrote that a driver's use or misuse of the driver-monitoring system "or operation of a vehicle in an unintended manner does not necessarily preclude a system defect".
Bryant Walker Smith, a University of South Carolina law professor who studies automated vehicles, said the agency document all but said Tesla's method of making sure drivers paid attention was not good enough, that it was defective and it should be recalled.
Monitoring a driver's hand position is not effective because it only measures a physical position.
"It is not concerned with their mental capacity, their engagement or their ability to respond," he said.
Similar systems from other companies such as General Motors' Super Cruise use infrared cameras to watch a driver's eyes or face to ensure they are looking forward.
But even these systems may still allow a driver to zone out, Dr Walker Smith said.
"This is confirmed in study after study," he said.
"This is established fact that people can look engaged and not be engaged. You can have your hand on the wheel and you can be looking forward and not have the situational awareness that's required."
Safety board recommends limitations on Autopilot use
In total, the agency looked at 191 crashes but removed 85 of them because other drivers were involved or there was not enough information to do a definite assessment.
Of the remaining 106, the main cause of about one-quarter of the crashes appeared to be running Autopilot in areas where it had limitations, or in conditions that could interfere with its operation.
"For example, operation on roadways other than limited access highways, or operation in low traction or visibility environments such as rain, snow or ice," the agency wrote.
Other automakers limit use of their systems to limited-access divided highways.
The National Transportation Safety Board (NTSB), which has also investigated some of the Tesla crashes dating to back 2016, has recommended that the NHTSA and Tesla limit Autopilot's use to areas where it can safely operate.
The NTSB also recommended that the the NHTSA requires Tesla to have a better system to make sure drivers are paying attention.
The NHTSA has yet to act on the recommendations.
The NTSB can only make recommendations to other federal agencies.
NHTSA questions why Tesla did not recall vehicles
In a statement, the NHTSA said there were not any vehicles available for purchase today that could drive themselves.
Driver-assist systems can help avoid crashes but must be used correctly and responsibly, the agency said.
Tesla did an online update of Autopilot software last year to improve camera detection of emergency vehicle lights in low-light conditions.
The NHTSA has asked why the company did not do a recall.
The NHTSA began its inquiry in August of last year after a string of crashes since 2018 in which Teslas using the company's Autopilot or Traffic Aware Cruise Control systems hit vehicles at scenes where first responders used flashing lights, flares, an illuminated arrow board, or cones warning of hazards.
ABC/wires
