Working road graders used to be one of Africa's most endangered species, but they appear to have made a big comeback since I last spent time in Africa more than 27 years ago.

We have seen significant numbers of the operational species in both Kenya and Uganda - in Kenya in the game reserves and conservancies and in Uganda on some of the big inter urban road building projects which have been underway for some time now. We even saw one in the Congo (pictured) - carrying out repairs to the road to the Wagenia Falls (near Kisangani).

You only see graders in the UK when new roads are being built but in Africa, where the majority of the roads are unsealed gravel, murram or sand roads, graders are vital for maintenance. The key to a decent unsealed road is good drainage - and that means having a good camber on the road to shed water effectively and working drainage ditches on either side to carry the water away.

The more it is used, the more the camber of a road gets worn away and ends up on either side in the drainage ditches - with corrugations and pot holes forming in the road surface. That's where the grader comes in - to scrape the drainage channels out with its blade and restore the profile of the road camber - so the comeback of operational graders is a very welcome sight.