Transportation choices primarily come down to two main factors: cost and convenience. That’s not news. When one or both of those factors become skewed against one mode of transport it’s assumed that a person will seek out an alternative to that mode or perhaps decide not to make the trip altogether. The question is: are these two factors equally important?

Furor over pat-downs and long lines for TSA screenings at airports and bag checks on Metro are just a few examples of the level of importance people place on convenience when traveling. Indeed new research indicates that convenience may even be the dominant factor in transportation decision-making. A recent study compared the GDP per capita of eight developed nations from 1970-2008 to the distance traveled per capita per year by various modes of transport. One of the most interesting findings as reported in Miller-McCune comes from what study co-author Lee Schipper calls “peak travel.” What he means by this term is that as GDP per capita reaches a certain level (usually between $25000-30000) the demand for travel reaches a peak and thereafter declines or stabilizes.

The results of this study the article notes “run counter to government models predicting steady growth in travel demand well beyond 2030.” The authors hypothesize that congestion parking and fuel costs may be contributing to peak travel. (Indeed a new study of urban bicycle behavior shows that commuting by bike in rush hour can be faster than doing so by car due to gridlock.) While this study includes all forms of travel (not just by auto the most energy inefficient form of travel) it does specifically note that auto travel and car ownership appear to be declining (or at least not increasing).

However promising developed world trends may be the developing world continues to adopt the automobile at a blistering rate. Seen as symbols of status and achievement new cars are now flooding the roads of Beijing at a rate of 700000 per year. That’s not at economically environmentally or mental-healthily sustainable and convenience will take precedence in the developing world as well as the drawbacks of congestion are made painfully plain. “Traffic is paralyzed everywhere and that will be an obstacle to motorization in the developing world in the end” Schipper said in the Miller-McCune piece. “There ain’t room on the road. You can’t move in Jakarta or Bangkok or any large city in Latin America or in any city in the wealthy part of China…Yes fuel economy is really important and yes hybrid cars will help. But even a car that generates no CO2 still generates a traffic problem.”