Another Way To Measure Car Dependence

I got into an argument on Twitter about how widespread car ownership was in NYC's outer boroughs, which in turn caused me to go to city-data.com to answer the question: how do you measure how many people own cars, anyhow? The City Data website has data not just for cities and counties, but for individual neighborhoods within a city.  In particular, the site gives data for household size and for the number of cars per household.

For example, I grew up in Northside-Mt. Paran, one of the most car-dependent neighborhoods in car-dependent Atlanta.  In this area, there are about 1.6 cars per household* and the average household has 2.0 people.  Thus, 80 percent of individuals have cars.  Since about 20 percent of the neighborhood's residents are in K-12 school, this means roughly every adult has a car.**

Even New York's more car-dependent outer borough areas are not as car-dependent.  In Douglaston, at the outer edge of Queens, there are 1.4 cars per household and 2.3 people per household.  Thus, about 60 percent of individuals own cars (and. deducting the usual 20 percent for people under 18, about 75 percent of grownups).

By contrast, Forest Hills in central Queens (where I lived for a year and a half) has about 0.9 vehicles per household, and the average household size is 2.1 persons.  Thus, only about 45 percent of Forest Hills residents own a car.  (16 percent of individuals are in K-12 school, so that means about 55-60 percent of grownups).

As you get closer to Manhattan, the number of cars declines still further.  In Long Island City across the East River from Manhattan, there are 2.4 people per household and about 0.8 cars per household- which means only 1/3 of people have cars.

What about Manhattan?  Manhattan's East Village boasts only 0.3 cars per household, in an area with 2 people per household- which means only 15 percent of people have cars, and about 20 percent of grownups (assuming 20% of people are under 18).

How do low-income neighborhoods compare to the (mostly affluent) neighborhoods discussed above?  Mott Haven is in New York's South Bronx, and its data contain a slight wrinkle: a huge gap between homeowners and renters.  Homeowners have 1.6 cars per household, renters only 0.3.   The City-Data site lists the number of rooms for owner and renter-occupied households, so with a little mathematics I could guess the number of each: roughly 10,000 owner-occupied, 30,000 renter-occupied.  So weighing the results appropriately, I came up with about 0.6 cars per household for the neighborhood as a whole.  Since Mott Havenites have larger households (3 individuals per household) that means about 20 percent of people have cars.  Because Mott Haven is a very young neighborhood (with 37.9% of individuals over 3 in K-12 school) this means that about 1/3 of grownups have cars.

*Actually, 1.2 per household for renters and 2.0 for owners.  But since there is a fairly even division between the two I split the difference for most neighborhoods, which I realize is an oversimplification. 

**There are also some high school students who have cars - but this number is probably canceled out by the number of people under 3 who are not included in my 20 percent.