How do people who commute via public transit differ from those who drive? I’ve been thinking about this question for a while. Based on what I’ve read, the prevailing wisdom today seems to point to widespread demographic differences between public transit commuters and car commuters. There is strong evidence suggesting economic and racial disparities between the two groups. I’ll talk about why one might expect each of those disparities, and then dig into the data to see how pervasive they might be.
There are clear cost advantages to mass transit over cars. In 2018, new cars cost had an average sale price of around $37,000. According to AAA, owning a car in 2018 cost an average of $8,849 per year (and this doesn’t take into account parking costs in large cities). In contrast, ValuePenguin reported that, on average, transit passes in large US cities cost around $67 per month, or $804 annually. Given this reality, it makes sense that transit riders would be more economically disadvantaged than car commuters. This difference could be measured through a number of economic markers, including lower homeownership rates and higher poverty rates among transit riders.
In addition to economic disparities between different kinds of commuters, one might also expect a racial disparity between car commuters and public transit commuters. A report from the American Public Transportation Association, Who Rides Public Transportation, found that 24% of transit riders are African American; in comparison, African Americans make up only 12% of the general population. The current racial makeup of public transit riders can be explained in part by generations of government policies throughout the 20th century that reinforced racial segregation in urban areas, which in turn contributed to de facto segregation of mass transit. Douglas Rae’s book, Urbanism and its End, describes how New Deal policies singled out minority neighborhoods made it difficult for nonwhite residents to secure home loans and build wealth. Post WWII, federally-subsidized development helped white city residents move to newly constructed suburban neighborhoods, while private sector discrimination denied nonwhite residents that same opportunity. This deepened the racial disparity between cities and suburbs.
Finally, there is evidence to suggest that immigrants are disproportionately likely to rely on public transit. A study by the Department of Housing and Urban Development’s journal, Cityscape, found that immigrants were less likely to own cars and more likely to use alternate modes of transportation. To approximate immigration status for the purposes of this article, I measured the percent of commuters who are not United States citizens.
I’m interested in understanding how these economic and racial disparities look across different cities. To do that, I compared income, poverty rates, homeownership rates, race, and citizenship status across 100 US cities. These cities had the largest total number of car and public transit commuters, as measured by the 2017 American Community Survey. The following five box plots show different demographic variables, for each city, for car commuters and public transit commuters. Each set of box plots allows the reader to sort each of the columns.
1. Median Earnings:
2. Poverty Rates:
3. Homeownership Rates:
4: Percent African American:
5. Percent Noncitizen:
For each of the five variables I looked at, the demographic difference between car commuters and public transit commuters was statistically significant. In general, the data from these 100 cities conformed to the expectations that public transit commuters are more likely to be economically disadvantaged, African American, or a citizen of another country. In some of the cities, particularly large cities in the Northeast and West Coast, the size of the disparity between car commuters and public transit commuters is more modest. There are even a handful of cities that do not conform to expectations, cities where car commuters actually had slightly lower earnings, higher poverty rates, etc. than public transit commuters.
The data I’ve presented aligns with existing studies, finding that public transit commuters are, as a group, disadvantaged compared to car commuters. And that disadvantage is compounded by policies that neglect or even undermine improvements and expansions of existing transit systems.
Historical development patterns as well as contemporary policies have shaped how accessible public transit is to commuters in different cities. Decades of disinvestment and political resistance to mass transit have limited transit infrastructure and had devastating impacts on urban commuters. This history played out miserably in cities like Atlanta and Tampa Bay, as an article from StreetsBlogUSA, “How Racial Discrimination Shaped Atlanta’s Transportation Mess,” and an article from The Tampa Bay Times, “A long way to go,” explain.
In any discussion of public transportation and who rides it, it’s worth noting that not all public transit systems are equal. While many cities on my top 100 list still don’t have light rail in 2019, Boston opened an operational streetcar in 1897. And today, Boston joins San Francisco, New York, and Washington, as home to one of the best public transit systems in the country. In those cities and others, taking public transportation every day sometimes means being able to afford living in expensive downtown neighborhoods that are transit-accessible. In a housing boom that prices residents out of urban centers and into the surrounding metro areas, daily public transit use in some cities is becoming a privilege. As housing costs continue to rise and urban neighborhoods gentrify, I would expect the demographic gap between public transit riders and car commuters to shift.
Data sources: United States Census Bureau
Programs: MS Excel, Tableau