WTF?! Police in the Canadian province of Alberta got a surprise when they chased down a speeding car that appeared to have nobody inside. It turned out that the Tesla was traveling down the highway with both driver and passenger asleep in their fully reclined seats.

The incident, which took place in July, came after highway officers received a call reporting a speeding Tesla Model S. When police approached the vehicle from behind, it was traveling at 140 kmh (87 mph), breaking the 110 kmh (68mph) limit. After the patrol car activated its emergency lights, the Tesla sped up to 150 kmh (93 mph).

"Nobody appeared to be in the car," RCMP Sgt. Darrin Turnbull told CBC News. He added that the reason it sped up when the police car's lights were activated was that vehicles ahead of the Tesla moved out of the way.

"Nobody appeared to be in the car, but the vehicle sped up because the line was clear in front," said Turnbull. "I've been in policing for over 23 years and the majority of that in traffic law enforcement, and I'm speechless. I've never, ever seen anything like this before, but of course the technology wasn't there."

The 20-year-old British Columbia man behind the wheel has been charged with speeding and issued a 24-hour license suspension for fatigue. He's also been charged with dangerous driving and served with a court summons for December.

We've seen several instances of Tesla vehicles moving down highways with drivers either asleep or sitting in the passenger seat. Tesla has repeatedly warned that its Autopilot feature isn't a fully autonomous system—it alerts drivers if it detects they're not holding the wheel with both hands. Should the warnings be ignored, the hazard lights are activated, and the vehicle automatically slows down and pulls over. But Turnbull notes that: "there are after-market things that can be done to a vehicle against the manufacturer's recommendations to change or circumvent the safety system."