I agree Frog - most Qataris are respectful on the road and I've been personally shown courtesy by Qatari drivers on many occasions as a pedestrian.
Let me state now that this driver was no young hoon - he was an respectable looking middle aged Qatari - He turned off into the government sector near the roundabout which leads me to believe he was a govt employee.
Having said the above, I categaorically believe that this place has the absolute worst maniac drivers I have ever encountered - and that includes experience in a number of third world countries and Riyadh. Ignorance and aggression on the road seems to be the norm here - my wife gets cut off and nearly run off the road virtually every second day on the way to school and back. I'll personally eat all my hats when I come across a Qatari in one of those damned Landcruisers that actually gives way on a roundabout.
There's a good reason why the government has introduced the toughest road rules in the middle east. It's to curb these idiots who have no respect for other users of the road. I personally will have no hesitation in reporting them to the police - that's if I don't end up braining one of them first!