File:Petrol use urban density.JPG

Summary
A graph showing the relationship between urban density and petrol use

Newman and Kenworthy’s 1989 study is often referred to in demonstrating a relationship between overall urban density and transport energy use. Newman and Kenworthy’s statistical methods have been criticised by a number of authors. The essential problem is examining the relationship between ‘motor spirit use per person’ and ‘persons per hectare’. Because population is in the denominator in one term and the numerator in the other, a spurious correlation emerges. Reanalysis of the primary data comparing gasoline use per person to area per person shows a more complex relationship. The revised graph shows this.