Driving on Zimbabwean roads is full of surprises and there will be a few more entries under What on earth?! that are related to roads and streets in Zimbabwe!
Re-treading used tires is no longer common, probably because of safety regulations so people have found other uses for them. As far as Zimbabwe goes, door mats and sandals are the most common. Strips of tire rubber are also useful to hold car suspension parts in an emergency (and often permanently!) and there are many other uses, I am sure.
We overtook this pick-up (I should say bakkie) loaded with a very ingenious way of re-using old tires. I would like to sit on one to see how comfy they are!