The National Highway Safety Agency in the United States (NHTSA) is expanding its investigation into accidents involving Teslas. It now concerns 830,000 cars (Model Y, Model X, Model S and Model 3) sold from 2014 by the company, i.e. almost all the vehicles sold by the company, and no longer 765,000 as initially announced in last August.
This investigation, which concerns the advanced driver assistance system (ADAS) called Autopilot, follows a dozen collisions involving parked emergency vehicles. The NHTSA now carries out a technical analysis (“engineering analysis”). A necessary step before the agency can carry out a possible vehicle recall, details Reuters.
17 collisions closely inspected
The NHTSA thus opens the last stage of its investigation, and must decide within one year whether the vehicle should be recalled or if the investigation should be closed. This follows an initial investigation by NHTSA in 2021 into 11 crashes with emergency vehicles. The agency has since identified six other accidents that have occurred in the past two years.
In most cases, Autopilot instructed the driver to regain control of the vehicle less than a second before impact. The emergency braking system intervened in at least half of the accidents. NHTSA also found that first responders on the road were visible to drivers an average of eight seconds before impact. But forensic data showed no driver took evasive action between 2 and 5 seconds before impact, despite all having their hands on the wheel.
Sufficiently attentive drivers?
NHTSA is examining whether Tesla cars sufficiently ensure that drivers are attentive. In the majority of cases, it seems that drivers comply with the standards put in place by Tesla and, for example, keep their hands on the wheel. The fact that the crashes weren’t averted therefore raises questions about whether Tesla’s warning strategy is sufficient.
NHTSA, as detailed by Reuters, said the update consists of “to extend existing crash analysis, evaluate additional data sets, perform vehicle assessments, and explore the extent to which Autopilot and related Tesla systems can exacerbate human factors or behavioral safety risks by undermining the effectiveness of driver supervision.”
The importance of human-computer interactions
In addition to the accidents mentioned above, the American agency looked into 106 other accidents involving Autopilot. In almost half of these accidents, the driver was “insufficiently responsive”. This would highlight the fact that if drivers actually have their hands on the wheel, they are not sufficiently attentive to their environment. A study by MIT researchers came to light last September that Tesla drivers are less attentive when the Autopilot system is engaged.
How a driver can interact with an in-vehicle system, and vice versa, is an important design consideration for Level 2 autonomous driving technologies. NHTSA added that “A driver’s use or misuse of vehicle components, or unintentional operation of a vehicle does not necessarily rule out a system fault.” Tesla must provide answers to the American agency which can then decide whether it intends to carry out a recall of the vehicles or not.