Two Tesla vehicles were tricked into going 85 in a 35 by researchers who put electrical tape over a speed limit sign.

The findings which were released in February, highlight the difficulties with autonomous drivings systems. The simple act of using black tape across the first digit of a 35 mph speed limit sign caused the vehicle's cruise control system to accelerate to 85mph.

Of course, the best thing to come out of this research is reading the twitter commentary:

In response to the first tweet, someone has in fact already drawn a looney tunes road runner tunnel to confuse drivers:

This is why we can't have nice things.