The Federal Highway Administration released its National Household Travel Survey last month, a massive poll of tens of thousands of Americans which is taken every eight years. The survey is considered one of the definitive sources of hard statistics about Americans’ travel habits and transportation needs, used by various transportation industries and infrastructure groups. This most recent National Household Travel Survey has revealed what many transportation analysts have been hinting at for years: Americans are driving less than they have in the past. However, in surprising news, the survey also revealed that millennials are actually driving more despite predictions that ours would be the generation to kill the automobile. What does this mean for the future of American transportation?

Well, it’s complicated. While the data reveal that Americans between 26 and 33 are driving more as the economy has recovered, they have also revealed a sharp gap between higher-income Americans and their lower-income peers. Since 2009, there have been some unusual trends observed in Americans’ driving habits: high and medium income individuals are driving fewer miles per capita, while low income people are driving more miles per capita.

This disparity is much more pronounced in the millennial age group (26-33 years old), where high-income driving has fallen nearly 70% in the last 18 years. Miles per capita among low income people in this age group has risen over 30% in just the last eight years.

While the data don’t exactly spell out the reasons for these figures, they do reveal much about disparities in access to urban housing. Millennials have been flocking to urban environments for years due to the ease of getting around, lower dependence on automobiles, and social activities. However, urban living comes with a high price tag and cost of living; thus, lower income millennials depend on the cars to get to their jobs more so than their higher income peers living in urban areas with public transportation.