Thanks to Mose on Facebook, verified on http://www.justitsministeriet.dk/arbejdsomr%C3%A5der/f%C3%A6rdsel/automatisk-fartkontrol
and because people are far better than websites, for information accuracy, look at the comments to this post:
"fartkontrol" is Danish for "speed check", "fartkontroll" is Swedish. It's simply a matter of there being one or two "l"s. Also, "fartskontroll" is the Norwegian term for it
It's true. Also when an elevator is moving (up/down) some elevators have a sign saying "I fart" which means "Elevator is moving"