I suppose, in practicallity, yes, the A9 should be duel'd throughout and should have been done when the road was upgraded.
Slow lorries can cause frustration and the inattention of motorists, in general, add to the risk. The A9 also has that added ingrediant to the dangers of the road - the tourist. These folk are on their holidays and will rubber neck at every mountain and castle. Their main problem is they are used to driving 'on the wrong side of the road' in their own countries and have difficulty when driving over here.
Today's motorist has many distractions to keep his attention off the road, like tuning in the radio, CD or Mp3 player. He also has to look at the screen of his Tom Tom or other Sat Nav gimmic and kerb crawling in the Carrbridge area. His mobile phone is also another distraction and don't tell me you don't use your phone whilst driving - even a hands free is a disrtaction you know.
The road is safe, its those that use it that need educating. Today's roads require full on 100% concentration - nothing less will do.