These things should be taught in school.
Under normal circumstances, all road users should have a good knowledge of road signs and their meaning. Pedestrians, cyclists and vehicle users (and if I might add hawkers) should be able to interpret these signs and adjust their usage of the road as the signs dictate.
But seeing as this is Nigeria and normal is overrated, the Tekes on their show today asked road users if they could read traffic signs and how much they obeyed. The responses they got were enlightening.
Have a listen here>>>