It is a summary of the average weekday miles traveled by adults in private vehicles, including taxis and ride-hailing vehicles, for the 50 largest metro areas in the US (data is from the fall of 2023). At the top of the list with the most miles traveled is Raleigh, and at the bottom of the list with the fewest miles traveled is, not surprisingly, New York.
The other cities on the bottom of this list probably won't surprise you either. But it's a good reminder of how built form determines our mobility choices. If you look up which US cities have the highest population densities and the most compact built forms, I think you'll generally find that it mirrors what you're seeing here.
This data is from 2019, but I imagine that things would look pretty similar today and that it might even be a little more pronounced. The dataset from the above article looked at how many people have cars in a given area (a darker dot = fewer cars) and then plotted this against population density and income per capita.
Here's what that looks like for the regions of New York, Boston, Los Angeles, and Houston (data from 2013 to 2017):
For a number of years now, urbanists – including myself – have been thinking about “peak car.” And that’s because if you looked at vehicle miles traveled (VMT) in the United States since about 2007, the trend line was more or less flat.
This had us wondering whether or it was simply an outcome of the recession or some sort of broader shift.
Well, if you look at the December 2015 numbers from the U.S. Department of Transportation, VMTs are once again growing. In fact, it’s now above the 2007 “peak.” Compared to December 2014, travel on all roads and streets in December 2015 was up by 4.2% or 10.6 billion vehicle miles traveled.
Here’s the chart:
A lot of this could be because of lower gas prices. But I would be curious to hear your thoughts in the comments about whether or not you think 2007 to 2014 was (1) a recessionary blip or (2) a longer term trend in the making.
What is fascinating about these charts is that they show two different correlations. In dense and transit-rich cities such as New York and Boston, car usage is most closely linked with population density and not with income. The dark dots form a horizontal line near the top.
However, in the case of Los Angeles and Houston, car usage is instead most closely linked with income and not with population density. The dark dots form a vertical line near the left -- the lowest income per capita.
So what does this tell us?
It tells us that if you design a city to broadly require a car, then you are likely to sort people based on those that can afford a lot of car and those that cannot. On the other hand, if you design a city around transit, then you are likely to instead create a place where both the rich and poor get around in similar ways.
There is also evidence that the latter is being increasingly viewed as more desirable. 2017 was the first year in the US where high-income young people (ages 26 to 33) drove less than low-income young people. Presumably these high-income people had choices, and so I tend to view this as a preference.
As a whole, this is surely a good thing for our cities. But now I think we need to be careful not to allow density and walkability to become the new luxury that only the rich can afford.
