Sprawl is not sustainable in that an organism with unnecessarily long pathways wastes energy. However, many cities are not "done" growing yet and we can't reall

Sprawl is not sustainable in that an organism with unnecessarily long pathways wastes energy. However, many cities are not "done" growing yet and we can't really say if a city of sprawl will eventually become an efficient city as it is refactored over time and as the selection pressures of the environment change (energy cost, maintenance, etc...).