Volvo wanted to demonstrate how precise and easy to control their new line of semi tractor trailer trucks were. So they decided to do something completely insane: ask champion slackliner Faith Dickey to walk a line between two trucks as they sped down a highway... towards a tunnel that would snap her rope.

And she did it, as you can see, although it was definitely a difficult and scary stunt. Even Faith herself, who walks lines set up hundreds of feet in the air, calls it "quite thrilling". Set up on a closed highway in Eastern Europe, the stunt manages to achieve what Volvo was looking for... except we're too busy biting our nails and hoping she manages to get onto the trailer OK.

You might be wondering why we're calling it "slacklining". The difference is the rope you walk: a "tightrope" is really a rigid steel cable. A slackline is an actual rope that moves much more and requires different muscles and balance.

Apparently the stunt required quite a few rehearsals. We're just impressed she did it at all.