On the map, it doesn't show very far. But according to Lonely Planet, a bus ride takes 10 to 12 hours. So I assume the road is very poor. Is it nevertheless possible to drive it on your own with a car? Are any special preparations necessary?
I used that road on a public bus in 2009, it wasn't that bad at all. It should be no problem to drive it yourself.
Public buses stop a lot for passengers and also do lunch and toilet breaks, that why they are usually much slower than a private car.