I want to drive from Johannesburg South Africa to Kigali Rwanda in August 2015. One leg of the route is concerning me. I see the distance from Mbeya to Tabora in Tanzania is 560km along the B 6 and Google says it should take just over seven hours to complete. My question is does anybody know what the road condition is like and is the 7 hour odd estimate correct? We will be two or three landcruisers.
You are right to be suspicious of an estimated 80 km/h speed on a dirt road in a convoy of loaded 4x4s.
However, looking at the satellite view, the road is fairly straight, wide, and flat. I budget closer to ten hours for the trip (plus stops). Of course this depends on driver skill and fatigue as well.