A tweet from Elon Musk indicating that Tesla might allow some owners who are testing a B次元官网网址淔ull Self-DrivingB次元官网网址� system to disable an alert that reminds them to keep their hands on the steering wheel has drawn attention from U.S. safety regulators.

The National Highway Traffic Safety Administration says it asked Tesla for more information about the tweet. Last week, the agency said the issue is now part of a broader investigation while using the Autopilot driver assist system.

Since 2021, Tesla has been beta-testing B次元官网网址淔ull Self-DrivingB次元官网网址� using owners who havenB次元官网网址檛 been trained on the system but are actively monitored by the company. Earlier this year, Tesla said 160,000, roughly 15% of Teslas now on U.S. roads, were participating. A wider distribution of the software was to be rolled out late in 2022.

Despite the name, Tesla still says on its website that the cars canB次元官网网址檛 drive themselves. Teslas using B次元官网网址淔ull Self-DrivingB次元官网网址� can navigate roads themselves in many cases, but experts say the system can make mistakes. B次元官网网址淲eB次元官网网址檙e not saying itB次元官网网址檚 quite ready to have no one behind the wheel,B次元官网网址� CEO Musk said in October.

On New YearB次元官网网址檚 Eve, one of MuskB次元官网网址檚 most ardent fans posted on Twitter that drivers with more than 10,000 miles of B次元官网网址淔ull Self-DrivingB次元官网网址� testing should have the option to turn off the B次元官网网址渟teering wheel nag,B次元官网网址� an alert that tells drivers to keep hands on the wheel.

Musk replied: B次元官网网址淎greed, update coming in Jan.B次元官网网址�

ItB次元官网网址檚 not clear from the tweets exactly what Tesla will do. But disabling a driver monitoring system on any vehicle that automates speed and steering would pose a danger to other drivers on the road, said Jake Fisher, senior director of auto testing for Consumer Reports.

B次元官网网址淯sing FSD beta, youB次元官网网址檙e kind of part of an experiment,B次元官网网址� Fisher said. B次元官网网址淭he problem is the other road users adjacent to you havenB次元官网网址檛 signed up to be part of that experiment.B次元官网网址�

Tesla didnB次元官网网址檛 respond to a message seeking comment about the tweet or its driver monitoring.

Auto safety advocates and have long criticized TeslaB次元官网网址檚 monitoring system as inadequate. Three years ago the as a contributing factor in a 2018 fatal Tesla crash in California. The board recommended a better system, but said Tesla has not responded.

TeslaB次元官网网址檚 system measures torque on the steering wheel to try to ensure that drivers are paying attention. Many Teslas have cameras that monitor a driverB次元官网网址檚 gaze. But Fisher says those cameras arenB次元官网网址檛 infrared like those of some competitorsB次元官网网址� driver assistance systems, so they canB次元官网网址檛 see at night or if a driver is wearing sunglasses.

Philip Koopman, a professor of electrical and computer engineering at Carnegie Mellon University, argued that Tesla is contradicting itself in a way that could confuse drivers. B次元官网网址淭heyB次元官网网址檙e trying to make customers happy by taking their hands off the wheel, even while the (owners) manual says B次元官网网址榙onB次元官网网址檛 do that.B次元官网网址� B次元官网网址�

Indeed, TeslaB次元官网网址檚 website says Autopilot and the more sophisticated B次元官网网址淔ull Self-DrivingB次元官网网址� system are intended for use by a B次元官网网址渇ully attentive driver who has their hands on the wheel and is prepared to take over at any moment.B次元官网网址� It says the systems are not fully autonomous.

NHTSA has noted in documents that numerous Tesla crashes have occurred in which drivers had their hands on the wheel but still werenB次元官网网址檛 paying attention. The agency has said that Autopilot is being used in areas where its capabilities are limited and that many drivers arenB次元官网网址檛 taking action to avoid crashes despite warnings from the vehicle.

TeslaB次元官网网址檚 partially automated systems have been under investigation by NHTSA since June of 2016 when a driver using Autopilot was killed after his Tesla went under a tractor-trailer crossing its path in Florida. The separate probe into Teslas that were using Autopilot when they crashed into emergency vehicles started in August 2021.

Including the Florida crash, NHTSA has sent investigators to . Nineteen people have died in those crashes.

Consumer Reports has tested TeslaB次元官网网址檚 monitoring system, which changes often with online software updates. Initially, the system didnB次元官网网址檛 warn a driver without hands on the wheel for three minutes. Recently, though, the warnings have come in as little as 15 seconds. Fisher said he isnB次元官网网址檛 sure, though, how long a driverB次元官网网址檚 hands could be off the wheel before the system would slow down or shut off completely.

In shutting off the B次元官网网址渟teering wheel nag,B次元官网网址� Fisher said, Tesla could be switching to the camera to monitor drivers, but thatB次元官网网址檚 unclear.

Despite implying through the names that Autopilot and B次元官网网址淔ull Self-DrivingB次元官网网址� can drive themselves, Fisher said, itB次元官网网址檚 clear that Tesla expects owners to still be drivers. But the NTSB says human drivers can end up dropping their guard and relying too much on the systems while looking elsewhere or doing other tasks.

Those who use B次元官网网址淔ull Self-Driving,B次元官网网址� Fisher said, are likely to be more vigilant in taking control because the system makes mistakes.

B次元官网网址淚 wouldnB次元官网网址檛 dream of taking my hands off the wheel using that system, just because it can do things unexpectedly,B次元官网网址� he said.

Koopman said he doesnB次元官网网址檛 see a great safety risk from disabling the steering wheel nag because the Tesla monitoring system is so flawed that disabling it doesnB次元官网网址檛 necessarily make Teslas any more dangerous.

NHTSA, he said, has enough evidence to take action to force Tesla to install a better monitoring system.

The agency says it doesnB次元官网网址檛 comment on open investigations.

B次元官网网址擳om Krisher, The Associated Press