It took California Highway Patrol seven minutes to pull over a Tesla driver. The driver appeared to be asleep at his wheel.

Alexander Samek had allegedly dozed off while operating his Tesla Model S when an officer tried to pull him over. In the end, the police had to surround the car to slow it down and then arrested Samek on suspicion of driving under the influence.

The Model S is thought to have been in Autopilot, Tesla's semi-autonomous driving mode. This is what would have enabled a sleeping Samek to keep driving for the seven minutes it took Highway Patrol to stop him. It's not currently clear if Autopilot was active, however.

Tesla steering wheels are fitted with sensors that can detect when a driver's hands let go of the wheel. A summer update to the Autopilot software made it so built-in alarms go off as frequently as every 15 or 20 seconds if the sensors can no longer detect pressure on the steering wheel. The cars are also programmed to come to a gradual stop if too many Autopilot warnings go unheeded.

It's not clear how Samek could have been asleep for the whole seven minutes it took to pull him over, given Tesla's built-in safeguards.

CORRECTION: Dec. 3, 2018, 9:10 a.m. PSTAn earlier version of this article incorrectly referred to Tesla Autopilot as a self-driving feature. We regret the error.