Safety —

Tesla driver blames Autopilot for crash, faces negligent driving charge

The driver reportedly told police he “must not have been paying attention.”

A red sedan cruises down a tree-lined highway.

A Massachusetts man is facing a negligent-driving charge after his Tesla slammed into a police car that was parked by the side of the road. According to a state trooper, the man had Tesla's Autopilot technology turned on and said that he "must not have been paying attention." The crash occurred in December, but the defendant, Nicholas Ciarlone, was only recently charged in the incident.

NBC Channel 10 in Boston reports that the police car was parked on the left-hand side of Route 24, a divided highway in West Bridgewater, a town about an hour south of Boston. The state trooper had just pulled over college student Maria Smith and was asking for her registration paperwork when the Tesla slammed into his SUV.

This caused a pileup, with the police car crashing into the student's vehicle. The trooper was knocked back against the concrete barrier at the side of the road but was not seriously injured. Smith said she got glass in her hair when the back window shattered. And Smith told NBC 10 that the officer easily could have sustained more serious injuries.

"If my car had pushed forward any more, he probably would've ended up getting crushed by it," she told NBC 10's Ryan Kath.

Teslas keep crashing into stationary vehicles

This is a known issue with Tesla's Autopilot—and with similar products from other carmakers. In 2018, there were at least two incidents where Autopilot crashed into parked fire trucks. Thankfully, neither crash led to any deaths. In 2019, a Tesla Model 3 crashed into a parked police car on a Connecticut highway. Police reported the driver was "checking on his dog in the back seat" prior to the accident.

In two other cases—one in 2016, the other in 2019—Teslas crashed into the sides of tractor trailers that were crossing in front of the vehicles. In both cases, the Teslas slid under the trailers, shearing off the tops of the vehicles and killing the drivers instantly.

As I wrote in 2018, this isn't uncommon behavior for adaptive cruise control systems. Often these systems use radar to match the speed of moving vehicles ahead. This is fairly easy to do with radar, which can directly measure another vehicle's velocity. However, such systems may completely ignore stationary vehicles since radar has poor angular resolution and can't distinguish stationary objects near the road (like a concrete lane divider) from an obstacle in the vehicle's travel lane. Adaptive cruise control works well enough most of the time, but it can lead to the rare case where, if a car is parked in the travel lane and a car with adaptive cruise control is being driven by a driver who isn't paying attention, the two can crash.

Tesla is aiming to build a more sophisticated self-driving system that fully understands the surrounding environment. Hopefully, Tesla's "full self-driving" software will eventually detect a situation like this and respond appropriately. But as of at least last December, the technology seems to still be a work in progress.

Channel Ars Technica