I've driven on quite a few real outback roads over the past 4 decades and they certainly are a vast improvement these days.

The popular triangle Darwin-Kakadu-Katherine-Darwin is what most tourists would use and they are quite good. Often as good or better than lightly populated parts of the USA and Canada where I drive several times each year for weeks on end.

Missed hitting quite a few roos on the Kakadu - Katherine road tho, in broad daylight.

Hit (and killed) a dingo in daylight last year driving from Broome to Adelaide River, that cost me $2750 in car rental excess.

This photo I took of the ex-Dingo clearly shows the road - perfectly acceptable for a road in that part of the world:

http://www.glenstephens.com/tr-Dingo...r%20Broome.jpg

On much outback road there is low scrub or no scrub, so a 100K limit is pretty silly I'd have to agree. The traffic is often very sparse so a higher speed is quite safe.

However, 57% more deaths occurred on NT roads in 2005 than 2004 and that might be behind this.