Redesigning cities to cater for vehicles is absurd. What is not as absurd, is redesigning cities for walking or "Walkability" as it's known to planning professionals. This is easily done by densification of key areas in districts, coupled with land rezoning allowing for mixed-use developments to occur where they are needed. The core idea is to create neighbourhoods which contain most amenities within a 10 minute walking distance, thereby reducing the need for vehicles altogether. In such circumstances, private transport companies will most likely flourish. The reason mass transit is such an issue (in South Africa) goes all the way back to the Group Areas Act which forced the working class to live really far away from their place of work. But you can't blame that alone, as Modernist planning principles suggested the same thing - compartmentalizing the city in "live, work, play" zones, as if cities are such a simplistic habitat, and can be so easily reduced to parts (they cant).