Facepalm: With more vehicles now equipped with some form of autonomous driving features, are people putting too much faith in these systems? Tesla's Autopilot, which is one of the most advanced on the market, was recently used to drive seven miles down a highway while the driver is alleged to have been asleep and drunk behind the wheel.

Police spotted the gray Model S belonging to Alexander Samek, the chair of the Los Altos Planning Commission, doing 70 mph on Highway 101 early Friday. As this was above the speed limit, officers pulled up alongside the car and noticed that Samek was allegedly asleep, leading them to assume it was in autopilot mode.

California Highway Patrol Public Information Officer Art Montiel said cops moved behind Samek's vehicle and tried to get him to pull over by turning on their lights and sirens, but he was "unresponsive."

The Tesla eventually came to a stop after another police car positioned itself in front of the vehicle and started slowing down. According to a press release, it still took a while for officers to wake Samek, who was then taken to a nearby gas station where he failed a sobriety test and was arrested over a suspected DUI.

The Autopilot system in Tesla vehicles alerts drivers if it detects they're not holding the wheel. It eventually slows the car down and stops it if the warnings are ignored. It's assumed the Model S in this incident managed to travel 7 miles because Samek had been putting pressure on the wheel as he slept.

Tesla has long emphasized that Autopilot does not make a vehicle fully autonomous, but is designed for use on highways that have a center divider and clear lane markings.

There have been several accidents over the years, some resulting in driver deaths, in which Autopilot was activated. But Tesla notes that its vehicles have traveled a total of one billion miles with Autopilot assistance.

Some owners continue to leave the driver's seat after the feature is enabled, including a UK man who was caught on video sitting in the passenger seat while his Tesla did the driving.