This makes no sense unless the distribution between rural vs. urban populations changes. If most of the projected population growth (to 10bb people by 2083 [1])

This makes no sense unless the distribution between rural vs. urban populations changes. If most of the projected population growth (to 10bb people by 2083 [1]) happens in areas where there is mass transit, then great - this seems plausible. If the % of the population growth continues to be what it is today (close to 50/50 [2]), then this just cannot be plausible. 5bb people in 2083 is unlikely to be result in fewer than the number of drivers that there are on the roads right now (roughly 1bb) [3]. [1] http://en.wikipedia.org/wiki/Population_growth http://en.wikipedia.org/wiki/Population_growth [2] http://www.un.org/en/development/desa/news/population/world-urbanization-prospects-2014.html http://www.un.org/en/development/desa/news/population/world-... [3] http://en.wikipedia.org/wiki/Motor_vehicle http://en.wikipedia.org/wiki/Motor_vehicle