Other ideas that have been tried
Cost and tradition are the vital marketing ingredients. Production is usually producer-driven not consumer. People produce what they have been taught to produce and don't often look for innovations. They have to be convinced that the improvement suggested will work and won't cost them too much.
The Kisumu Innovation Centre manager, Martin Osumba, talks almost wearily about the efforts they have made to change people's thinking. There is an experimental bicycle rickshaw at his workshops. Although these have been successful elsewhere in the world, it has not caught on in Kenya.
They have also tried using panniers at the sides of the back wheel to carry baggage but again this has not been an accepted innovation.