A factor rarely mentioned is heat. People in tropical climate do not enjoy walking even relatively short distance because of its hot and humid weather during m

A factor rarely mentioned is heat. People in tropical climate do not enjoy walking even relatively short distance because of its hot and humid weather during most of the year. Middle-class people in dense tropical cities with traffic problems still buy a car as soon as they can afford it. Coupled with barebone funding for and low quality of public transportation, the traffic problem gets worse and worse as people become more affluent and cities get denser. Bangkok was a legendary example, where its skytrain only recently helped mitigate the problems for those rich enough to afford a place to stay close to one of its stops.