About 56% of the world lives in urban settings. I wouldn't call 45% of the population a niche market, however I would say that even a significant portion of the rural population could be better served with non-car transportation options. Removing fossil fuels as much as possible from our energy use will still be vital to averting a major crisis, and alternatives will need to be found for those 45%, too, especially since they will use proportionally more transportation energy than their urban counterparts.