Tesla owners cannot seem to catch a break these days, or, at least, in the ways most drivers would expect to. Following a multi-model recall in which the company disabled a self-driving feature that allowed the affected cars to roll through stop signs, another automated feature is coming under scrutiny. The NHTSA has now received over 100 complaints about something called phantom braking.
The Washington Post spoke with Carnegie Mellon University professor Phil Koopman. Mr. Koopman studies autonomous vehicle safety. “Phantom braking is what happens when the developers do not set the decision threshold properly for deciding when something is there versus a false alarm,” Mr. Koopman said.
The NHTSA has said that it is aware of complaints about instances where owners have reported their vehicle’s forward collision avoidance system, or ADAS, is engaging prematurely. In essence, the car is hitting its brakes for no apparent reason, hence the name, phantom braking. The agency says that it is reviewing the complaints through its risk-based evaluation process. The process will involve discussions with Tesla along with the review of multiple data sources, and if the risk is confirmed, immediate action will be taken.
NHTSA is aware of complaints received about forward collision avoidance and is reviewing them through our risk-based evaluation process. This process includes discussions with the manufacturer, as well as reviewing additional data sources, including Early Warning Reporting data. If the data show that a risk may exist, NHTSA will act immediately. -Lucia Sanchez (NHTSA Spokeswoman)
Rise in Complaints
Reports on the auto-braking feature have been on the rise for months. According to The Washington Post, there were over 107 complaints in the last 90 days, while there had only been 34 in the preceding 22 months. November saw the highest amount, with 51 filed complaints. One complaint to the NHTSA, reprinted by Electrek, illustrates the inconsistency in which phantom-breaking events have been occurring.
Upon accepting delivery at the end of May we have accumulated 9,000 miles on the car and have a had horrible experiences with the traffic aware cruise control slamming on the brakes for no apparent reason with nothing ahead or passing cars. Behavior can be 5-10 mph slowdowns or in some cases FULL brake pressure which puts us in danger of being rear ended. Multiple times we have been close to rear-ended. -NHTSA (via Electrek)
Multiple owners have expressed their concerns when using cruise control that if a vehicle is following too closely behind them during one of these incidents, an accident will happen. Most drivers can easily imagine such a scenario. Factor in bad weather or poor visibility conditions, and things could go from bad to worse fairly quickly. Let’s not even try to add the risk of a distracted driver into the mix.
Some have noted that their experiences worsened after a software update in November. Other owners also noted in May, that when Tesla switched from radar to a vision-based system called Tesla Vision on its Model 3 and Model Y cars, their vehicles had then begun to brake abnormally. The uptick in complaints also paralleled to when both changes to the auto-braking system were rolled out.
Sources: The Washington Post, Electrek (1, 2)