Today, the prevailing wisdom seems to point to widespread demographic differences between people who commute by public transit and people who commute by car. A quick google search reveals strong evidence suggesting both economic and racial disparities between the two groups, a trend that’s backed by substantive research. I’ll talk about why one might expect each of those disparities between those who drive and those who take public transit, and then dig into some American Community Survey data to see how measurable these differences are.
One might expect a large economic gap between car commuters and public transit riders. The reason for that is pretty simple; there are clear cost advantages to public transit. In 2018, a new car had an average sale price of around $37,000. Taking into account maintenance and gasoline costs, AAA found that owning a car in 2018 cost owners an additional $8,849 per year on average. And that doesn’t even include high parking costs in large cities. In contrast, transit passes in large US cities cost only $67 per month, or $804 annually, according to ValuePenguin. Given this reality, it makes sense that transit riders would be more economically disadvantaged than car commuters. This difference probably gets reflected through a number of economic markers, including lower homeownership rates and higher poverty rates among transit riders.
In addition, there is evidence to suggest that immigrants are disproportionately likely to rely on public transit relative to cars. A study by the HUD’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.
Finally, one might also expect racial disparities 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 overrepresentation of African Americans in mass transit can be explained in part by the racial wealth gap, but it may also be attributable to 20th-century housing policies. Douglas Rae’s book, Urbanism and its End, describes how New Deal policies prevented nonwhite residents from secure home loans and and buying in more desirable neighborhoods. Post WWII, federally-subsidized development paid for white city residents to move to newly constructed suburban neighborhoods, while the aforementioned policies, combined with private sector discrimination, denied nonwhite residents that same opportunity. These generations of government policies reinforced racial segregation in urban areas, which in turn contributed to the de facto segregation of mass transit. Based on this history, it is likely that the racial gap between urban and suburban residents will be reflected in commuter demographics.
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