Throughout human history one overarching story has been that as our society became wealthier we traveled more. The reality that our ancestors generally were born, lived and died in the same place with rare opportunities to “see the world” is hard to deny – so is the reality of our world where it is not unusual to find people walking the streets of our cities who woke up that morning on a different continent and rubbing elbows with masses of people who have lived, gone to school and worked in a wide and complex array of places.

But new academic research is suggesting that the upward surge in travel that has become such a feature of our world may have come to an end.

This could be very similar to well documented phenomena of air pollution rising as a society becomes more wealthy but then reaching a point where the relationship between economic activity (or income) flips -   air pollution increasingly declines as wealth/income rises.  This is know as an “inverted U-Shaped Kuznets curve” by economists (who are almost as poetic when they name things as lawyers).  This analysis suggests that as income rises people collectively take action to reduce pollution.  There is some controversy about applying this principle to pollution that is not as visible and obvious – like the Carbon Dioxide (CO2) that is a major cause of global warming, but some scholars believe that as income and wealth rises that emissions of CO2 drop very suddenly after a critical break point under some conditions.

But the possibility that we may have passed a critical “break point” where travel stops growing would be very good news in terms of slowing and reversing global warming given the critical role of the transportation sector in the emissions of these greenhouse gases – and the major role that travel growth plays in driving (pun intended) such emissions.

These trends are not handed down from above though – whenever we choose to build communities where people can walk, bike or even drive short distances to their offices, schools, stores, friends and families who move our world in a positive direction.  And when we build good transit systems that allow us to move around those communities quickly and cleanly everyone benefits.