This figure shows how travel by age cohorts are varying in the Twin Cities from household travel survey data. Persons born in the most recent cohorts make fewer trips than persons born in earlier decades at the same age. We are not talking just about Millennials; this is true of Generation X as well. From Levinson and Krizek (2015) The End of Traffic and the Future of Transport. http://davidlevinson.org/the-end-of-traffic-and-the-future-of-transport/ Figure 1.5 Source: Iacono, Michael and Levinson, David (2015) Travel Behavior Over Time: Cohort Analysis of Travel Behavior. Center for Transportation Studies, University of Minnesota.