• The character of neighborhoods is greatly influenced by the prevalence of cars. Residents of some parts of America get by with fewer cars, typically either dense urban areas, or ones that are less affluent.
  • Whether getting by with fewer cars is a positive outcome largely depends on the reason for it — getting by without being able to get around comes at a human cost.

In this suburban nation, cars are generally a necessity. But in some parts of America, people are at least getting by — and hopefully, also getting around — with fewer cars.

U.S. households have an average of 0.68 vehicles per capita — or put another way, the average vehicle serves less than 1.5 people. But in New York City’s Harlem neighborhood, the average vehicle serves more than 10 people. In Harlem, the combination of a relatively low-income population and a dense urban environment amenable to public transit seemingly lends itself to fewer vehicles per capita. But does that logic hold more generally? And where outside of New York City — with its massive, dense urban core that is unique among American cities — might people be getting by with fewer vehicles?

As part of a broader effort to shed light on the nature of neighborhoods throughout the nation, at Trulia we have mapped every metro area with respect to the number of people per vehicle, using data from the American Community Survey. To help surface those areas where people get by with fewer cars, ZIP codes within metro areas were ranked (the numbers presented reflect the combined period from 2013 to 2017).

Select a metro area:

Download the full set of zip code rankings, nationally and within each metro area

More Density, Lower Income = Fewer Cars

The maps and the data tell a remarkably clear story. People get by with fewer cars in areas which:

  • Have greater population density
  • Have lower levels of income

Lower incomes, for their part, mean people are less able to afford a vehicle. And greater population density does two things: First, it makes space for parking more scarce and so, all else equal, more costly. Second, greater population density allows places to support public transit that is both more frequent and more efficient. Pricier parking and better transit both discourage the use of vehicles.

Take the Los Angeles region for example. The area around Downtown L.A. has relatively high numbers of people per vehicle — and so does the 15-mile stretch of land south of downtown, where both population density and local incomes are much lower relative to other parts of the metro. In contrast, the parallel stretch along the coast from Santa Monica to Palos Verdes is almost as dense, but far more affluent — and thus has far fewer people per vehicle.

Select a metro area:

Download the full set of zip code rankings, nationally and within each metro area

Income and population density are two of the most obvious factors at play, but other factors such as the local population’s age matter too, and they often relate to income and density in complicated ways. Because children can’t drive, the number of people per vehicle is higher in areas with more kids (though not with more elderly residents). All else equal, a greater share of children also means lower income per capita (because kids don’t usually work), and usually coincides with lower densities because parents are likely to choose neighborhoods with less of a premium for indoor and outdoor space.

Where Do People Live With Fewer Cars?

Nationwide, the cities with the fewest people per vehicle (or the most vehicles per capita) are those which are both affluent and the most overwhelmingly suburban. Among large metros with over 1 million residents, the Knoxville region leads the pack with as few as 1.31 people per vehicle, followed closely by the Dayton and Denver metro areas with 1.36 and 1.37 people per vehicle respectively.

At the other extreme, the Fresno metro area has 1.79 people per vehicle and stands out for having particularly low-incomes and a young population with a relatively large share of residents too young to drive. The New York region, in league of its own with 2.11 people per vehicle, is unique for its uncharacteristically large and dense urban core.

Download the full set of metropolitan rankings

The same pattern repeats itself across neighborhoods (ZIP codes) within metros, but the relative importance of density and income is not always the same. Take New York and Boston: In these metros it is density — not income — that is most clearly associated with the number of people per vehicle (especially in the denser parts of these metros). At the same time, in Los Angeles and Houston it is income, not density, that is more closely associated with that number.

The discrepancy between the patterns in Boston and Houston is consistent with Houston consisting almost exclusively of low-density suburbs and Boston having a sizable, centuries-old, dense urban core surrounded by rings of lower-density sprawl. On the other hand, the contrast between Boston and Los Angeles — which is relatively dense by American standards but is newer and more car-centric than Boston — suggests an important role for public transit infrastructure. Public transit allows residents to take advantage of density and forego vehicles, but its presence tends to derive from the period in which an area was built.

Not all metro areas fall clearly into one pattern or the other. Some have a mix of the two, such as Chicago.

Select a metro area:

Download the full set of zip code rankings, nationally and within each metro area

Getting Around, or Just Getting By?

In an age in which an urban lifestyle is often championed as a means of reducing carbon emissions and mitigating climate change, it is tempting to view elevated numbers of people per vehicle as something good. But it’s not that clear cut. If local residents are making do with fewer cars because alternatives to driving such as walking or using public transit are viable, it makes sense to view higher numbers of people per vehicle positively. But if people are living with fewer cars not because they have a better alternative but because they cannot afford them, that’s a much different story.

If these people could get around more easily, could they have an easier time getting by?

Data and methodology:
The maps, charts and insights in this article draw on data from the 2013-2017 5-year American Community Survey, published by the U.S. Census. ZIP code level population and income per capita figures are drawn directly. The number of vehicles per capita and its inverse, the number of people per vehicle, are obtained as the ratio of the aggregate number of vehicles in occupied housing units in an area and the total population living in those units. The analysis is confined to metro areas with populations over one million, and to zip code areas with more than 400 residents per square mile and in which more than 80 percent of the population lives in households (non-household populations include people living in college dorms, military bases, prisons, etc.). The insights reported are based on regression analysis of the data. More detailed information is available upon request.