Original sentence: A large percentage of Auckland is dominated by a very suburban style of building, giving the city a very low population density: although it has not much more than a seventh of the population of London, it sprawls over a considerably larger area
Edited sentence: A large percentage of Auckland is dominated by a very suburban style of building, giving the city a very low population density: although it has not much more than a seventh of the population of London, it sprawls over a considerably larger area - a fact that serves to make public transport by Auckland's rail and bus systems unpopular and uneconomic (car usage costs fall slightly with decreasing urban density, while public transport costs rise sharply, even if less capital-intensive types like bus services are used in the less dense zones)