Is this the most shocking anti-speed ad | video

Brutal footage aims to stun drivers into not speeding, but government department calls it 'sensitive'.

The shock-effect commercial shows a car crash through a park and kill a group of children. But officials from the Department of Environment in Northern Ireland, which released the ad, say the footage is 'sensitive'.

The footage shows a classroom of young kids playing and then enjoying a field trip to a park, while cutaway scenes show a man grabbing a hurried breakfast before getting into his car.

You can guess what happens next. In very blunt footage, the car loses control, smashes through the park wall, spins and rolls over the top of the children, with a voiceover saying speeding has killed 28 children -- a classroom's worth -- since 2000. "Shame on You," it finishes.

Northern Ireland minister for road safety minister Mark H Durkan has defended the ad as 'sensitive' and 'thought provoking'. "This campaign is a real wake up call. It is a particularly sensitive and compelling message," he told Irish media. "After all, what could be more thought provoking than the realisation that, since 2000, the equivalent of a classroom of children have been killed as a result of speeding."

In Australia we've seen some similarly brutal ads showing people being maimed or disfigured, usually mounted as campaigns against drink-driving, while New Zealand has done the same with a child in the back of car that crashes in slow motion. 

Perhaps the question is not whether the Irish commercial is more shocking than those, but whether it will work any better -- with no evidence that the campaigns do much to alter behaviour on the roads.